More In Depth Bash Commands

Question 1

What command searches a specified file and returns all lines in the file containing a specified string?

Searching for a certain keyword in a file

Answer 1

grep

grep OS updates.txt

grep is the command.
OS is the arguement we are looking for
updates.txt is the file we are looking into

Searching for a certain keyword in a file

Question 2

What sends the standard output of one command as standard input to another command for further processing?

Answer 2

| (Piping)