With cohorts you can group users who have taken a certain action in your app and track their subsequent actions over time.
Cohorts can be used to measure retention, engagement or a variety of essential business metrics such as how long it takes on average for a new user to transact.
From the CleverTap blog:
Customer retention is one of the most critical metrics for any business
Retention cohorts show you how many new users come back every day, week or month
How many days/weeks did it take for the majority of the users who launched app first time to purchase.
How many users who searched my product catalog returned the following week?
How long did it take first time purchasers to make their second purchase?
Cohorts let you go deep into your data to answer difficult questions about your App
Compare how groups of users from different Geographies are engaging.
Determine how many new users come back to use your app broken down by your ad campaigns.
Compare usage and retention across different types of devices. All these insights right at your fingertips.