Can someone explain js regular expression?

Question

Tried learning w3schools.com javascript regular expression and did not understand at all...
Ill be happy if someone could ezplain it more..
https://www.w3schools.com/js/js_regexp.asp

Answer 1

regex will capture the input and match the regex expression to the input if it matches it makes it through validation ..... like .*@.* (for email validation) basically says search any character up to a @ and any characters after the @...so if it finds the @ this expression will trigger in an if statement for validation and go through but if no @ it won't

Answer 2

practice with some text to see what it can do in regexr.com

Answer 3

regex is often used with php curl to get only the info you want to show or use from the curl

Answer 4

regular expression allows you to capture or replace specific string or character content

Answer 5

I have seen regular expressions that are used to validate forms age/email etc.. How does it work?