Disk Space

Disc space (also known as web space) is the amount of data you can store on the hard disk of the web hosting server. Each web hosting client receives a certain amount of space, which is usually between 100 and 1000 MB.

The amount of space you need primarily depends on the size of the website you wish to host. Generally, most websites are made of text pages (in HTML), images and graphics (in various formats) or Flash/scripting animation. When it comes to occupying web space, text is a very economical option as it uses very little space. On the other hand, images, heavy graphics, and flash can be more expensive and require a lot of space.

When you get your website designed, make sure you incorporate images and Flash with care, lest they end up occupying substantial disk space, leaving less space for more essential components of the site. Your aim should be to maintain the lightest possible page size, including images. Such light pages not only consume less space, but also load quickly, thereby helping retain user attention. However, if you want to host a website that is laden with heavy graphics or runs an exhaustive ecommerce platform, you should ideally opt for more web space.

Bandwidth

Bandwidth, or as it is known Monthly Traffic, is the amount of data that you're allowed to transfer per month through your web hosting server. This data is inclusive of all uploads and downloads, regardless of the protocol used (HTTP, FTP, POP).

When you decide upon your bandwidth requirements, keep two essential things in mind –your average page size as well as the number of visitors your website will have and the average number of pages they visit.
For example, say your website has an average page size of 30 KB, about 20,000 visitors per month and 3 pages per visitor, you will approximately need 1800 MB of bandwidth per month.
Almost all web hosting packages that you come across will offer this amount of bandwidth. Of course, your requirement will finally define what you should opt for.

Shared Hosting

Commonly referred to as 'Basic Hosting', it is the kind of server that most customers end up with. A simple, non-complicated and highly economical choice costs as low as $4-10 per month.
Shared hosting is ideal for small-time businesses that have basic, static websites, or individuals who simply want to host their blog or have their own ‘space’ in the online zone. In shared hosting, multiple single websites are shared on a single server and user has limited control over the server’s functioning.

VPS Hosting

Under VPS hosting, multiple websites can run on a single web server. However, the biggest difference it has from a shared hosting package is that a VPS Client can run his own operating system on the server. To cite an example, say both Website A and B are hosted on the same server. VPS gives A the flexibility to run on a Unix platform, even as B runs on a Windows platform. A VPS web hosting package generally costs somewhere between 55$-250$ per month or more (including its maintenance). 

Dedicated Hosting

Dedicated hosting is the most advanced and expensive (it generally costs between 250$-500$ per month or even more than that) type of website hosting service available.
A dedicated hosting service is when a client leases an entire server which is not shared with anyone. A single website is run on a single server, giving the webmaster complete control of the site’s administration and functioning. Highly flexible and better than shared hosting in terms of control, dedicated servers give users the choice of operating system, hardware, etc.