PostHog is an incredibly broad platform, with many distinct features and tools. As a result, it's hugely powerful -- but can be overwhelming if you're new to product analytics. So, we've created a glossary to explain many of the most common terms and acronyms. If a term is specific to PostHog then it's marked with a hedgehog 🦔 to help reduce confusion.
Actions in PostHog are a way to organize events into a different format. In their simplest form actions consist of one or more events which have been given a new name - usually a descriptive title, such as 'Viewed Glossary Page`. Find out more about actions in PostHog.
Active users are the people who currently use your product. A user who becomes inactive may have churned.
A related user account. In PostHog, aliases can be used to connect two user accounts (and their data). For example, combining the data of an anonymous user with their signed up account. See more in identifying users.
Annotations are short text notes you can apply to your data to help you understand context at a later point, or to signal important context to others. A common use for annotations it to add them shared charts and mark important events, such as feature releases or new marketing activiity. Find out more about annotations in PostHog.
Apps are additional features or functionality built on top of PostHog. They are commonly used to integrate PostHog with other platforms, modify events or enhance PostHog's functionality. Apps may be built by the PostHog team, or by the community. You can browse the app library to see what's available, or find out more in the docs. Formerly known as plugins.
App chain 🦔
In PostHog, the output of one app can impact the actions of the next app to create a chain. This makes it crucial to understand the order in which apps run. Find out more about app chains in the docs.
Annual recurring revenue - basically how much revenue you expect to make each year.
A/B tests are when you test two versions of an idea by serving each version to portion of your userbase, so you can monitor which performs best. If you're using more than two versions, it's a multivariate test. PostHog can do both, via Experiments.
Business to business. It's when you make money by selling things or services to other businesses, rather than to individual users. Tools such as Group Analytics are especially important for B2B users in PostHog.
Business to customer. It's when you make money by selling things or services to individual customers, rather than to other businesses. Tools such as experiments are especially important for B2C users in PostHog.
Business Associate Agreement, or also known as a Business Associate Contract. It's a legal document signed by contractors who may have to handle personal health information in order to agree to and satisfy the requirements of HIPAA. Find out more about PostHog and HIPAA.
Cost of acquisition. The amount spent on marketing, promotion, or advertising to acquire a customer. You can calculate CAC using the formula
Amount of money spent on customer acquisition / number of customers acquired.
When a user stops using your product and is no longer considered to be an active user. The speed at which users churn is known as your churn rate and, if it is greater than the rate at which you acquire new customers then your product is in decline.
Computing infrastructure, power, services, or storage hosted for on-demand usage with less required user setup and maintenance. You can choose to host your instance of PostHog in the cloud by choosing PostHog Cloud, instead of self-hosting.
Cohorts are groups of users in PostHog, created using the Cohorts tool. Cohorts can be created as either a static list, or a dynamic list which continues to update. Cohorts and groups are similar, but not the same.
As an open source company, PostHog enables anyone to add to our codebase or to submit ideas, either as issues or PRs. When someone does this, they become a contributor and can earn rewards such as merch, invitations and public thank yous. Sometimes, they even get hired. We love our contributors - check them out!
Conversion is when a user of your product changes into a new, usually more desirable, state. For example, converting from a lead into an active user. You can use tools such as funnels to track users who convert between states.
The act of complying with laws or regulations such as HIPAA or [GDPR](](/manual/glossary#GDPR). Find out more about how to use PostHog in compliance with common regulations.
Cost per Acquisition. How much it costs you to acquire users through an advertising campaign using the formula
Cost of the campaign / number of successful conversions. \
Call to Action. A message intended to elicit an action in your users, like this one: Star PostHog on GitHub!
Click-through Rate, or what proportion of users which saw a CTA actually clicked it. CTR is usually a good measure of engagement.
Dashboards in PostHog enable you to save multiple useful pieces of information, such as insights, into one place. This makes it easier to collaborate, as you can share dashboards with others in many different ways. Find out more about Dashboards in the docs.
A data lake is a system for storing raw data. The data stored in a data lake is usually for an ambiguous or unknown purpose, but the style of storage means all data is easily accessible to seasoned professionals and can be quickly updated.
A data warehouse is a system for storing processed data. The data that's stored in a data warehouse is usually for a specific, known purpose and is in constant use. As a result, the data is highly accessible but it can be slow and costly to make infrastructure changes.
Daily Active Users. Basically, how many active users you have each day. You can track this in PostHog using a simple trends chart.
In PostHog's lifecycle insight a dormant user is one who did not complete the specified action within the currently viewed period, but had completed it in the previous period.
In product and marketing terms, engagement is how involved or active someone is with your product. A regular user would be said to have high engagement, or to be highly engaged.
Events are the core building block of PostHog. Any activity a user does, such as clicking a button or viewing a page, is an event. Events are ingested into PostHog, and sometimes organized as actions.
Feature flags are used to divide users into two groups - those for whom the flag is enabled, and those for whom the flag is disabled. Based on this flag status, users are served a version of the product where a specific feature is, or isn't, available. Find out more about feature flags in the docs.
Every time you visit a website or view content from a website, you are served a
cookie - a data packet which contains information on your visit. First-party cookies are those which are served by the website operator and are typically used to store only user preferences. Users who self-host PostHog are able to collect additional information through their first-party cookie because PostHog is also deployed onto their servers. See also: third-party cookies
An equation or calculation that modifies data from one or more series.
Free Open Source Software. FOSS products are exactly as they are described: free, and open source. PostHog has a FOSS version too!
A funnel is a concept used to track users through a series of actions, such as from pageview to registration and login. In PostHog, you can use the funnel insight to track how many users move through each stage, and where drop-offs occur.
General Data Protection Regulation. GDPR is a regulation within the EU which governs how data must be processed, protected and kept private - notably by keeping it on servers within EU jurisdiction. Find out more about complying with GDPR while using PostHog.
Groups in PostHog enable you to aggregate events by anything other than an individual user, such as a company, team, device, project or pricing tier. Groups are different to cohorts and can be used for group analytics.
Go-to Market. In short, it's the plan you have for how you will bring a new product or feature to market, often building in intelligence on your users gained from product analytics.
Heatmaps enable you to visualize user activity as an overlay on top of the page, with warmer colours used to represent where the most activity takes place. In PostHog, heatmaps are used to track where users click. Find out more about PostHog heatmaps](/manual/toolbar), which are enabled via the toolbar.
Incredibly cute creatures which are sadly becoming increasingly rare around the world. Hedgehogs are recognisable for their prickly backs, dislike of badgers and ever-changing fashion habits. PostHog's mascot is a hedgehog called Max, who was designed by our Graphic Designer, Lottie.
Health Insurance Portability and Accountability Act. It's a piece of legislation in the US which covers, among other things, how personal health information must be handled. Find out more about how to use PostHog in a which complies with HIPAA regulations.
The process of collecting, connecting, and combining data to a user. Also the process of de-anonymizing a user with properties.
Users within your team. Often you'll want to remove internal users from your analysis to avoid swaying results with biased data. Find out how to filter internal users from your PostHog insights.
A metric for understanding the virality of your product. You can calculate your K factor by figuring out the number of invitations or recommendations about your product which users make, then multiplying it by the success rate of those invitations or recommendations. Any result greater than 1 indicates viral growth, as every user you acquire will, on average, successfully invite another.
Key Performance Indicator. A measurable metric which enables you to judge the success (or failure) of a person, team or product. Typically, teams may have multiple KPIs they are accountable for.
Lifetime Value. The total amount of revenue you get from the average user before they churn, calculated using the formula
number of users / total revenue.
Monthly Active Users. Essentially, how many users you have using your product each month.
Month-on-month or month-over-month. Normally this is used to track your performance from one month to the next, e.g. "We grew revenue 10% month-on-month".
Marketing Qualified Lead. A person who has indicated interest in a product based on activities taken by the marketing department, such as adverts or downloading marketing content. See also: PQL
Monthly Recurring Revenue - basically how much revenue you expect to make each month.
Minimum Viable Product. In other words, the simplest (and usually cheapest and fastest) version of something which you can build to test an idea. We build a lot of MVPs.
New user 🦔
In PostHog's lifecycle insight a New User is someone who was first identified within the specified period, and who did the investigated event in that same period.
A single metric or objective which guides your decision making. Find out more about how to set north stars and why they matter.
Net Promoter Score. A metric for understanding customer satisfaction and loyalty, based on asking users how likely they are to recommend your product, on a scale of 0 (not likely) to 10 (certainly likely). Users are then grouped into buckets based on their score - those who score 9-10 are labelled as Promoters, while those who score 0 to 6 are labelled as Detractors. Everyone else is labelled as Passive. By subtracting the percentage of Detractors from the percentage of Promoters, you determine an NPS score between -100 (very poor) and +100 (excellent).
Objectives and Key Results. OKRs are, like KPIs, a system for organizing team goals and measuring performance. Unlike KPIs, OKRs involve setting ambitious goals and judging performance in hitting them.
A model of distribution which involves giving others the ability to inspect, modify, and share what you create. PostHog is an example of both an open-source product, because we distribute our software under an open source MIT license, and an open source company, because we work with transparency.
In PostHog, a path is a visualization of a users' activity achieved using the path analysis insight. Paths enable you to see, for example, all the pages which users who visited a particular page viewed afterwards.
In PostHog, persons are used to aggregate the behaviour of an individual user, whether or not that user has been identified. Find out more about Persons on PostHog.
Personal Health Information. Regulations such as HIPAA require that any information about an individual's health must be processed and store in accordance with law.
Personal Identifying Information. Under some regulations, such as HIPAA, any information which can be used to identify a user - such as their birthday, ethnicity, or address - must be processed in accordance with law.
A managed stream of data connecting data creation, modification, storage, and access.
A rapid change in company direction. One of our favourite hobbies.
A way of adding extra functionality to PostHog, or integrating with other systems. We don't call them plugins anymore, though. We call them apps.
Product Qualified Lead. A PQL is a user who has expressed interest in your product based on actions which can be attributed to the product, such as completing a free trial or having experienced the direct value of the product.
Analytics services which focus on tracking identified and anonymous users and how they interact with your product. Product analytics services, such as PostHog, typically involve more detailed analysis tools than web analytics tools as a result of being able to focus on idenfitied users.
Sometimes this means Public Relations and refers to working with journalists and members of the media. But when we say PR, we usually mean a pull request, because we don't really do the other sort of PR outside of major announcements.
In PostHog, events and persons contain additional information, called Properties. A property can be any information stored on the object, such as which device they are using or their geographic location. Find out more about using properties in PostHog.
An event when someone makes a change to a piece of software. The best thing that anyone on PostHog's team can ever be doing.
The users a feature flag is active for. For example, the internal team, or 50% of all users.
In PostHog, a retention insight is used to visualize how many users return to your product after first visiting it on a particular day. Find out more about measuring retention on PostHog.
Returning user 🦔
In PostHog's lifecycle insight a returning user is one who did the specified action within the current period and within the previous period.
Resurrecting user 🦔
In PostHog's lifecycle insight a returning user is one who did the specified action within the current period but not within the previous period.
Security Assertion Markup Language is a system which enables users to login to multiple systems with one set of credentials. Find out more about SAML on PostHog.
Software development kit. Tools for building and using a software platform. PostHog has many SDKs available.
Segmentation is a way of dividing users into groups based on either demographic, geographic, behavioral or technographic properties.
The ability to host and manage software yourself (on your own servers). PostHog provides the ability to self-host.
Structured Query Language (pronounced "sequel"). A programming language for designing, building, and querying relational database management systems.
Single Sign-on is a system which enables users to login to a system (such as PostHog) using their access to another system (such as Google Workspace) as their credentials. Find out more about SAML on PostHog.
In PostHog, a stickiness insight enables you to see how many times users perform an action within a set period of time. Find out more about measuring stickiness with PostHog.
Every time you visit a website or view content from a website, you are served a
cookie - a data packet which contains information on your visit. Third-party cookies are those which are not served by the website operator and are instead served by third-parties, typically advertising companies. Users who self-host PostHog are able to collect additional information through first-party cookies because PostHog is also deployed onto their servers.
In PostHog, the toolbar is a widget in your browser that contains easy access to useful actions or information. PostHog's toolbar lets you easily inspect elements, view page [heatmaps]((/manual/glossary#heatmap), create actions, and toggle feature flags. Find out more about using the toolbar.
In PostHog, a trend insight is the default insight type and enables you to plot data from PostHog onto a chart. There are many different chart types and options which can be used when creating trend insights, including formula. Find out more about trend insights in PostHog.
User Generated Content refers to any content which users create within, or using your product for the purpose of sharing with others. Posts on Instagram are a typical example of user-generated content.
Urchin Tracking Module. Essentially, a UTM are modifiers appended to an existing URL in order to aid attribution in marketing campaigns.
Different versions of an experiment. In PostHog, variants are linked to feature flags, which activate them.
Virtual machine. An emulated and often isolated computing process. We use VMs to run apps.
Analytics services which focus on tracking anonymous users and how they interact with your content. Web analytics services, such as Google Analytics, typically involve less detailed analysis tools than product analytics tools and cannot track user identities.
Year-on-Year. Normally this is used to track your performance from one year to the next, e.g. "We grew revenue 10% year-on-year".