In C program, comments doesn’t have any use other than for better understanding of the developers of the source code in case you are writing big program and wants to remember what is the functionalities of the code blocks (functions/lines) in program.
Single Line Comment — Any text on a single line after // is considered as single line comment.
Multiline Comment — Any lines between “slash” “star” and “star” “slash” are considered as comments.
In C, you can’t have nested comments. Meaning you can’t write as,
/* … some comment 1 … /* … some comment 2 … */ */
This will not be a Valid nested comment.