How can i split my site in different "parts"?

I'm a noob in programming web pages and I was wondering, how can I split my site (i'm using filezilla to upload in it) in different parts? For example google is divided into many "parts" like maps.google.com, drive.google.com ... Is it possible to do this using a web hosting service like I'm doing right now? Sorry if it's a dumb question, thank you.