In contrast to other methods that may seem similar on the surface, such as linear regression, survival analysis takes censoring into account. Censoring occurs when the start and/or end of a measured value is unknown. For example, suppose our historical data includes records for the two customers below. In the case of customer A, we know the precise duration of the subscription because the customer churned in December 2020. For customer B, we know that the contract started four months ago and is still active, but we do not know how much longer they will be a customer. This is an example of right censoring because we do not yet know the end date for the measured value. Right censoring is what we most commonly see with this form of analysis.
Click through for an intro as well as a half-dozen notebooks.