PIP stands for "Performance Improvement Plan". I don't have experience with one, but from what I've read, it sounds like management-speak for "We're going to find a reason to fire you". Michael O. Church has an interesting perspective [0]:

""" Most people think of “performance improvement” as something well-intended, because they take performance to mean “how good I am at my job”....

However, that’s not what “performance” means in the context of a employment contract. When a contract exists, non-performance is falling short of an agreed-upon provision of the contract. It doesn’t mean that the contract was fulfilled but in a mediocre way. It means that the contract was breached. """

0: https://michaelochurch.wordpress.com/2012/12/24/never-sign-a...

To dissent with the others, I suggest that it stands for "pretext instead-of payment" rather than "performance improvement plan".

If you are ever given a PIP, polish up your resume and look for a new job, immediately. Your company is trying to fire you without giving you either the grounds to sue them or compensatory payment. You will also need to record and regularly back up all interactions with your superiors until you leave. There is no meaningful way to recover from a PIP without a judge or union rep on your side. Your career with that company is over.

Performance Improvement Plan - it's when you get "evaluated" for "underperforming" but is really just often used as a first step to getting rid of someone.

Performance Improvement Plan. In other words, it provides legal protection when they fire you.

Performance Improvement Plan

performance improvement plan