What is a Plugin?
A plugin is a code package which is available for installation, for extra features on a website.
What Language are Plugins Written in?
Plugins are written in CSS/HTML/PHP
Jobs they can do:
Plugins can do many things, such as SEO, security, UI, UX, look of a page, etc
What kinds of issues can arise?
Outdated plugins can be hacked, or there could be problems with them, plugins such as Wordfence can protect you from that
How do you maintain them?
You can prevent damage by removing the plugins you do not need at the moment, and keep them updated