In simple terms:
You write content for another site → they publish it → you get exposure and a backlink.

Why it’s important:

Builds high-quality backlinks (helps SEO)

Increases website traffic

Improves brand authority

Connects you with a new audience

Example:
If you have a digital marketing website, you write an article for a popular marketing blog and add your website link to it.

Short idea:
“Guest blogging = Write for others → Gain traffic, trust & SEO power.”