A web host is a computer, commonly called a server, on which the web site resides. If you are considering purchasing a computer for your web site, this is generally what you will need:
- A PC based system or better yet a minicomputer.
- Server Software to serve your web site to the Internet.
- An account with an ISP for continuous connection.
- At least an ISDN line to the ISP. A T1 line would be better.
- A special modem to handle the line to your ISP.
A typical small corporate server with support equipment and medium speed connection will cost an initial investment of $20,000 to $50,000. On top of that, you would have the monthly cost of a leased medium speed data line at around $3,000 for a T1 line. Plus add in the full time support personnel and the cost climbs way past what most companies can afford.
Since owning and maintaining a web server is an expensive endeavor, companies have sprung up who specialize in "Hosting" web sites. They invest in large high-speed computer systems running UNIX or Windows NT and have high-speed data lines connecting them to the backbone of the Internet. They then resell space on their servers to companies at much less cost. This is what is referred to as virtual domains where one system hosts 2 to 5000 web sites. The more web sites on a system, the less the expense will be per web site.
These same companies offer dedicated servers running UNIX or Windows NT. Depending on the requirements, these can be small Intel based systems or larger mini computers based on Sun, Alpha, IBM or HP. Generally, dedicated servers will start at around $1500.00 per month and include a 1.5 to 10mbps (Megabits per second) connection to the Internet.
Redundancy is a major factor. Most companies in the business of hosting multiple sites have multiple large battery backup systems each capable of running the data center for 1/2 hour or more and the capability is usually 125% to 200% of the power requirements. Most of these data centers are also backed up with diesel generators which will "kick" on-line if the power is lost for more than 5 minutes and again have the capability of 125% to 200% of the power requirements. A few companies go so far as to have multiple power substations being feed by different power grids and each substation is capable of running the complete data center individually.
Another option is to have multiple servers in different parts of the country serving the same web site. This is referred to as a mirrored site and is more costly than a single server site. The good part about this is if an area of the country is hit by a natural disaster, the other data center is still in full operation. If you are running an E-Commerce web site and is your sole income, this may be the only choice.
