A web hosting is a virtual space attached with each domain. You can create your website and keep the files on this space. Your other services like emails, payment gateways etc. also runs from these hosting space spread over many servers. There are two popular operating systems for web servers those are Windows and Linux servers.
In easier words domain name is the identification of each website on the internet. There are many extensions available to register as per the choice and nature of activity of your organisation, like .com is mostly used by commercial organisation whereas .org is for non profit making organisations. Select and register the domain name of your choice at http://dom.aviweb.in