Why is it advised to close a file after we are done with the read and write operations?

Q. Why is it advised to close a file after we are done with the read and write operations? What will happen if we do not close it? Will some error message be flashed?

Answer :-

Closing the file releases the resources. On a large system running many process you can use up all of the resources to keep track of open files. This may prevent any process from opening another file. When the process ends or crashes the OS is supposed to clean up for you.