I have difficulty defining 3rd UI party packages for my Angular app correctly (I joined an existing project).

Please, be understanding. I've read about 3rd party libraries but I still have a problem and want to define it correctly.

For example: ngx-sharedbuttons - I use it to display social buttons. Is that UI 3rd party package?

What about

• rxjs -> it's not, I believe, but maybe I misunderstood the topic
• ng-recaptcha
• file-system
• sitemap-generator
• outdated-browser-rework
• @fortawesome/angular-fontawesome
• @angular/forms
• @nguniversal/express-engine

if anyone could explain in own words... I will be really grateful