In general a single domain is primary one for setting up your hosting...addon can be added later if wished for multiple sites.multiple domain hosting may refer to more than 1 domains but u have to buy from host itself but that should not be such. Addon domains are domains registered at other places & added in your host.
Depends on the hosting providers. Some hosting plans can have multiple domains hosted in it irrespective of where you buy your domains from. Addon domain hosting : you have xyz.com domain registered with a hosting provider which could provide add on domain hosting. An add on domain allows you to have separate web site to your primary domain. When you create an add on domain it makes a folder in your public_html folder where you will have to upload the site contents. For multiple domains hosting solutions, you will have public_html for each of t he domains. I hope it helps,
sat123 thanks humdomains thanks . ya i got the point. but whats the main benefit of having diff public_html ( is it have any priority over server ?)
The only advantage of having multiple domain hosting could that you can have a IP assigned to each site whenever needed in future (if the traffic to your site increases with time) Best wishes,