Bandwdith is related to amount of data transfer , uploading and downloading .
(basically it is related to the traffic that will visit on your website ) There is a particular amount of data which has to be transferred through the website that has to be calculated wisely; otherwise you may land up making your website unavailable for the visitors.

Bandwdith is generally misunderstood with data transfer. They both are different practically and in terms of terminology. Data transfer signifies the actual data which has to be transferred every time your website loads. Bandwidth is a vehicle of certain capacity which transmits the data.

Your website’s bandwidth can be calculated using a simple formula which uses size of your website, number of pages your website has and number of visitors your expect for your website in a day.

Say for example, you have 3 pages on your website and on an average including graphics, images etc. your page size comes to around 40KB. You may have 80 visitors on your website in a day and they might take a look at all the three pages. So the bandwidth of your website per day should be

40KB X 80 visitors X 3 pages= 9600 KB

The webhosting service provider will be keen on knowing the bandwidth you require on monthly basis as they would be having appropriate plans for the same.

Sometimes domain hosted is misunderstood by customers that they are getting domain included in the hosting plan . But in actual Hosting (also known as website hosting or Web hosting) is the business of serving, and maintaining files for one or more websites.

In a sense, you rent space on a computer to hold your website. Your host, the computer where your website files are stored, assigns an address (DNS) for your files to your domain name so that anyone can find your website on the Internet by typing in your domain name.

Depending on the type of plan you have, certain things on your account are indeed unlimited. For example, shared accounts give unlimited disk space and bandwidth. When companies say unlimited, what they mean is that they do not meter or limit you on that item. But just because you can have an unlimited amount of something does not mean it is physically possible to consume an infinite amount. Unlimited does not mean infinite.In shared hosting even if unlimited plan is there , some Resouce usage restrictions are still there because in shard hosting only 25% of cpu is provided .

For example, when you go to an all-you-can-eat buffet, you can eat an unlimited amount of food. However, it is impossible for you to eat an infinite amount of food because of the size of your stomach, the number of hours the restaurant is open, how much food is physically available, and the fact that you cannot share your food or take it home with you. Certain rules for the buffet are put in place so one person does not come in and take all the food from all the other paying customers.

Similarly, it is not possible to use an infinite amount of the server since there are other limits in place, like how much CPU you can use at one time, how many processes you can have open at one time, how many emails you can send out in an hour, etc. Certain rules are in place to make sure one person does not use the entire server on a shared account, preventing other customers from using the server.

Any hosting customer is allotted a specific amount of disk space on the server they’re purchasing. The amount of disk space needed depends greatly on the type of website.

Storage is the space used for uploading files and for creation of mails and for creation of database means storage space comprises of HTML files, images, Flash files, databases and so on. Email accounts, raw access logs and any installed programs or scripts are also included in the total.

Linux and Windowsare two different types of operating systems.Linux is more secure and more efficient than Windows. Linux also has more of the features web designers expect,so unless you have websites which need specific Windows applications, Linux is the preferred choice.Windows applications which require a Windows server: ASP.NET
MSSQL
MS Access
Visual Basic development
Remote Desktop (dedicated servers only)

One other difference is that Linux files are case-sensitive and Windows files are not.

Example:
On a Linux server, home.html and Home.html are different names.
On a Windows server, home.html, Home.html, and HOME.HTML are the same name.
By the way, it doesn't matter if your computer runs on Windows, because all computers are able to communicate with Linux or Windows servers.

WHEN SHOULD YOU CHOOSE LINUX HOSTING :- Linux is often thought of as the best operating system for web servers. With its characteristic reliability, stability and efficiency Linux proved itself in complex web and mailserver environments. If you want to use PHP, Perl or MySQL, Linux is the operating system of choice because Linux hosting is well-suited for blogs, content management systems, online stores and forums.

WHEN SHOULD YOU CHOOSE WINDOWS HOSTING :-Windows makes it possible to execute conception frameworks, .NET framework or SharePoint. In this case Windows has a big advantage when you want to add special Windows applications to your website. Some of them are ActiveServerPages (ASP), .NET script languages, VisualBasic or using Microsoft SQL databases (Access).

To add other domains in your existing hosting you need to follow these steps.

1) Update Domain NameServers First of all you need to update nameservers of the domain you want to host in your existing hosting plan.

Use these Nameservers for your second Domain:- you have to use exactly same nameservers which you used for your first domain (i.e main domain used to purchase hosting).When you purchased hosting account we sent these nameservers in your welcome email. Check your Email Or If your First domain is working fine with hostaye then you can check those nameservers from this link also www.intodns.com.

Updating Nameservers:- After that Login to your domain panel and update domain nameservers as required. Nameserver updation can take upto 24 hours. Wait for few hours after updating nameservers.

2) Add your Domain using "Addon Domains" option of cpanel.

Note :- You may not be able to create an Addon Domain if you do not own (register) the domain name, or if your name servers (DNS) have not propagated.

With Addon Domains you can host multiple different domains with different website content, all under the same disk space and bandwidth of one cPanel. To create a second domain name with its own website, please do the following:

Login to your cPanel and click Addon Domains, under Domains. There are three fields cPanel asks for when creating an Addon Domain.

New Domain Name:- Enter the new domainname.com, but do not put http or www in the name.

Username/directory/subdomain Name:- This will be the folder cPanel creates in your public_html folder. Normally, you want to ensure the name you provide doesn't already exist as a folder in public_html, but cPanel will automatically suggest the name and we recommend you stick with the suggestion.

Password:- Fill in any password you want here. This password is used for an FTP account which is automatically created by cPanel. You likely will not ever need this password, so we suggest picking a random password and forgetting about it. Your new domain is now successfully added. You can upload the website files to the specific addon folder which was created in the public_html folder.

Reminder :- Your new domain name will not display your site until you set that domain's name servers. You must go to the company where you registered your domain, and change the name servers there. it can take upto 24 hours to display your site online after adding addon domain.

An addon domainis a fully functional domain that can be created from within your control panel. Think of it as having multiple hosting packages all sharing the same control panel. You can give them email addresses, forwarders, and more the same way you do for your main domain on the account.

The addon domain will appear as a totally separate domain from your primary domain. There should be no evidence that your domain is an addon domain to incoming traffic when they visit your addon domain. In a sense, you rent space on a computer to hold your website. Your host, the computer where your website files are stored, assigns an address (DNS) for your files to your domain name so that anyone can find your website on the Internet by typing in your domain name.