What is host ( Hosting ) ?

What is the importance of hosting or host in its website (blog)
The host at the website means "storage"
Two things have important role in the website
 (1) Domain
(2) host
Domain name is the address of our website such as google.com
And host is the memory card of our website and when we buy hosting, we have to choose a plan. Such as - 1GB - 2GB - 10GB - 100GB - unlimited etc. So, as many as you can buy GB plans, you can assume that we are buying a memory card for our website.
And without a hosting website, can not be created because whatever data we upload to the website is saved in the host itself.

For example
You have a phone and you have not placed any memory card in it and there is no internal memory in it.
So think of this situation if you can put something in it like - songs, images, notes, videos etc.
no never ! Because there should be storage for anything and there should be empty space
This is exactly the same as the host when we set host on a website generator with a domain, and then only upload any data on it.

Host, memory card is the only difference between these two that the memory card is accessible and the host is accessible online