Difference between shell and command in ansible

Question

I am new to ansible world can anyone help me in understanding the difference between shell and command in ansible. When to use shell and when to use command. I know one use case

Answer 1

according to documentation :

shell – Execute shell commands on targets

It is almost exactly like the command module but runs the command through a shell (/bin/sh) on the remote node.

and:

command – Execute commands on targets

The command(s) will not be processed through the shell, so variables like $HOME and operations like "<", ">", "|", ";" and "&" will not work. Use the shell module if you need these features.

[edited to delete non-decent language]

Answer 2

The Ansible Shell Module allows you to run arbitrary commands on a remote host, just like you were logged into the shell. The Shell and Command modules are very similar, the major difference being that the shell module does not escape commands, allowing you to use shell operators like redirects ("greater than", "less than"), pipe ("|") and boolean operators ("&&", "||"). This does mean that the Shell module is susceptible to command injection/shell injection, but this is easy enough to overcome by using the "quote" filter when using variables with the Shell module.

Reference: Ansible Shell Module Tutorial - Complete Beginner's Guide