What is the cat tool?

cat is a UNIX utility that reads file's content and output it on the screen.

Say, for example. There's a sample.txt file in your current directory, this file contains the following text.

Lorem ipsum dolor sit amet, consectetur adipiscing elit, 
sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. 
Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. 
Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. 
Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.

When executing the command cat sample.txt, the above text block will be outputted on the Console screen.

That's how most people use cat, it's a pretty simple UNIX utility, but like all UNIX utilities, cat comes with its own set of [options] & [flags], and can pipeline w/ other utilities for doing more complex thing, you may check out cat's man page documentation for more details.

Thank you...

BTW windows version for this command is 'type'