cat
Unix-like operating system command
cat is a standard Unix utility that reads files sequentially, writing them to standard output. The name is derived from its function to catenate files.
It has been ported to a number of operating systems. Wikipedia
Function: Concatenate files and print on the standard output
Syntax: cat -benstuv file ...
Example: cat file1 file2 > file3
Developer(s): AT&T Bell Laboratories
Initial release: November 3, 1971; 52 years ago