Is inline JavaScript good or bad?

[CyberAlchemist]

I am currently running WordPress sites and sometimes I have to add external scripts to develop my sites. It is hard to avoid to add JavaScript codes to files.
One thing I notice is that each time I add them, it embeds inserts JavaScript inline in the web page. Although it seems the JavaScript code is placed below the footer, it's still inline.
I've always been thought that JavaScript should be placed in JavaScript files. My question is inline JavaScript is good or bad? why? Or should I still try to keep JavaScript code in separate files?

 

[smsmbooster]

You should keep javascript and CSS in a separate files (.js and .css) to improve loading time of your page.

Because browser will cache Javacript and CSS files and won't re-load everytime customer access your site.