Collections are usually used for blog posts or similar pages. In Next.js they are referenced in dynamic routes.
Collections / blog
Getting Started
getting-started
10 Tipps for Facebook Marketing
10-tipps-fb
Create Your Perfect Google Ad
create-your-perfect-add
SEO Done Right
seo-done-right
How to Get More Traffic to your Website
more-traffic
Conversions 101
conversions-101