What is the purpose of self-executing function in Javascript?

Question

I don't know Javacript a lot. I am still a begineer. Asking this just out of self curiosity why do we use self executing function in Javascript ?

Answer 1

Self-invoking expressions are automatically invoked (started) without being called. 

A self-invoking expression is invoked immediately after it has been created. This is basically used to avoid naming a conflict, as well as to achieve encapsulation. Outside of this function, the variables or declared objects are not available. To avoid problems of minimization (filename.min) always use self executed functions