The basic idea of bash scripting is to execute multiple commands to automate a specific job.
As you might know, you can run multiple commands from the shell by separating them with semi colons (;):
ls ; pwd
The previous line is a mini bash script.
The first command runs, followed by the result of the second command.
Every keyword you type in bash scripting is actually a Linux binary (program), even the if statement, or else or while loops. All are Linux executables.
You can say that the shell is the glue that binds these commands together.