What is the use of blue dot in remix ide?

When I usually write my code in remix solidity a blue dot usually appeared on the left side with code line’s numbers as follows:

Kindly tell me what is it for?

Thanks for the help 🙂 .

>Solution :

That is called a breakpoint. Remix has a debugging feature that helps you debug transactions and analyze them line by line.

You can toggle a breakpoint by clicking on the space on the left side of the line number