Helpful definitions – Amplitude

Term	Definition
Active user	By default, an active user is a user who has logged at least one event during your selected interval: real-time (five minutes), hourly, daily, weekly, or monthly. You can edit this definition by marking certain events as inactive. Users who have only performed inactive events would no longer be counted as active users.
New user	A new user is one who has logged an event for the first time (this includes inactive events). The time of when the user is new is the time of when they logged their earliest event.
Unique user	A distinct individual to whom events are attributed. Amplitude uses a system of identifiers to count unique users. In the raw data, unique users are counted using `amplitude_id`.
Session	A period of time that a user has your app in the foreground. By default, events within five minutes of each other are combined into a single session on a mobile app. On web, events within 30 minutes of each other are combined into a single session.
Event	An action a user takes in your product. This could be anything from pushing a button, completing a level, or making a payment. Depending on your product, you should aim to track between 15 and 200 events to get a full understanding of how users are engaging with your app.
Event property	Reflects more detailed information about an event at the time it was tracked. These properties depend on the type of app you have and the specific information you think is necessary for understanding a particular event. General keys we have seen are cause, description, category, type, duration, level, % completed, name, count, source, status, from, number, lives, authenticated, error, rank, action, and mode.
User property	Reflects traits about the individual person using your app. Examples of custom user properties are locale, referral source, plan type, number of photos uploaded, number of units of in-game currency, and current level in a game. The most important thing to remember is that these user properties reflect the state of the user and apply across all their events.
Behavioral cohort	A set of users with shared behaviors and properties, e.g. users who have made at least five purchases within the last 30 days.
Stickiness	Measures the number of different days/weeks a user performs an event in each week/month interval.
Retention	Measures how often your users are returning to your app over some timeframe.
Funnel	A customized series of events a user goes through to successfully do something in your app, such as successful onboarding.
Amazon Redshift	A fully managed petabyte-scale data warehouse that contains Enterprise customers' Amplitude data.
[Amplitude]	A prefix Amplitude uses to mark user properties it automatically tracks through its SDKs.
Amplitude ID	A unique ID used to identify a particular user across multiple User and/or Device IDs.
User ID	A unique ID used to identify a user, e.g. email address or username.
Device ID	A device-specific identifier. For iOS, the Device ID is the `identifierForVendor` (IDFV). This does not persist across installs. For Android, we generate a random Device ID that gets stored locally on the phone. However, there is a flag to use the Advertising Identifier as the Device ID if you want. The Advertising Identifier does persist across installs but users have the option of changing this identifier on their devices at any time. See a detailed explanation for how the value is obtained here.
Event ID	A counter distinguishing events. Event IDs are associated with the device ID.
Session ID	Represents the number of milliseconds since epoch (UTC) of when the first event of the session occurs.
[Amplitude] Any Active Event	Any event you are tracking in Amplitude that has not been marked as inactive.
[Amplitude] Top Global Events	The top 10 active events by event totals at the time of the query.
[Amplitude] Top Events for Segment	The top 10 active events by event totals at the time of the query for the specific segment (in the chart's right module).
[Amplitude] Any Event	Any event you are tracking in Amplitude, regardless of activity.
Inactive event	Events are configured as inactive in Govern. Amplitude users typically configure inactive events as events that aren't tied to an action done by the user but still occur within the app or website. One such example is a push notification or email sent to the end user.

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