What is bottleneck?

A bottleneck is when one part of a process slows everything else down, like a traffic jam on a highway.

Imagine you and your friends are making a big tower out of blocks. Everyone is working hard, some stacking, some bringing more blocks, others counting them. But then, one friend is really slow at passing the blocks to the next person. That one slow step makes the whole team move slower, even though everyone else is fast. That slow friend is like a bottleneck, they’re holding everything back.

Sometimes a bottleneck happens because one part of a process is just not ready for the work coming its way. Like when you're trying to drink from a straw, but the straw is too narrow, it slows down how fast your juice can go into your mouth.

Or think about a cookie factory: if the oven only cooks 10 cookies at a time, but the rest of the factory makes 50 cookies every minute, that oven becomes a bottleneck, it's the slowest part and limits how many cookies can be made.