In simple terms #1:

A DOMAIN is like the name on a book.

HOSTING is like an empty book. It gives you the space to store your information and images.

A WEBSITE is the information and images that go inside the empty book.

In simple terms #2:

A DOMAIN is like the address of your house.

HOSTING is the land or the space in which you are given to have your house and furniture.

A WEBSITE is then like the house/building and the furniture inside it.

In technical terms:

A DOMAIN name is the name and/or address of the website, i.e. www.thedomainname.com

HOSTING is a service provided by a vendor which offers a physical location for the storage of web pages and files.

A WEBSITE is a collection of pages that contain information: images, words, digital media, etc.