Any idea about shell programming ??

Question

What is it ?? And How to learn it ??

Answer 1

Shell/Terminal is where you put command I.e installing, updating, attacking..
In Linux family os

Answer 2

The Linux Command Line, 2nd Edition: A Complete Introduction
by William Shotts (Author)
best one in my opinion

Answer 3

Is there an app like Sololearn to learn shell programming ?