What makes the web so important?
Worldwide access and connection.
The earliest mass use of hyperlinked documents was electronic encyclopedias, whereby readers could seek definitions and related ideas while reading text.  Modern web pages are connected by telephones, cables, and satellites from one computer to another throughout the globe.  You do not have to physically possess the information in order to use it. Modern web pages contain code for not just text and pictures, but music, search tools, embedded calculators, shopping cards, discussion forums, and databases for price quotations.  Web pages can gather information such as election votes, and credit card orders, and can send the client to another web site.  The present language of the web, hypertext markup language, or HTML, is based on more-or-less internationally agree standards.  There are some annoying variations in how HTML gets implemented, but it's basic coding is so simple that's it not even called a program.

Is the web safe?
Wasn't that a line from Dustin Hoffman?
Yes, it's safe.  Sort of. Web pages are handy because they can activate powerful computer programs such as databases without the remote user, or client, fiddling directly with the program.  Unlike direct computer-to-computer connections, the web is a potentially safer environment for everybody.  The client's relationship to the host is "stateless," that is, there is no connection, only a series of requests from client to host.  Often this can provide anonymity to the client.  As long as the web designer is careful, there is little chance of damage or theft of information, in either direction.  However, the programming tools needed to cross the stateless barrier, for placement of an order, submission of a credit card number, and validation of user identity, are vulnerable.  The downloading of executable forms of information, programs, is always vulnerable.

What is a domain name?
A domain name, e.g., baker.com, is a special part of a web address, like a street name.
A domain is a uniquely named web address containing one or more periods.  Multiple web pages, usually all pages within a web site, can share the same domain name, but are distinguished by various naming conventions including slashes.  "Domain name" is normally used to describe the portion surrounding the last period, e.g., "baker.com" in a web address.  Technically this is a second-level domain, while com is the top-level domain. There are seven top-level domains administered in the United States, and several hundred more around the world.  The other top-level domains in the United States are net, org, edu, gov, mil, and us, and each is usually used for certain kinds of entities.
By tradition, the "dot com" domains have the strongest brand name distinction, thus they are preferred even by networks, non-US companies, and some organizations.  A second-level domain address which is a "dot com" is usually easier for people to remember, in the same way that if you tell someone that you live on a 42nd Terrace, or Way, or Avenue, they might get confused and think you meant 42nd Street.  If you could locate your organization on a street, people would more likely remember your address.  With web domain name you can do better than that, you can buy the street.  $70 gets you your own "dot com," though using it will cost more.

Does my business or organization need its own domain name?
Yes, if you're serious.
Owning a "dot com" or other second-level domain name has strong advantages. People are more likely to find you, because they will either remember your address, or will be more likely to type it into their computer without error.  This is because a domain name is relatively short and distinctive, maybe the same as or a reflection of your trademark or corporation name.  While the majority of new contacts will find you electronically through search engines, and will not have to know your address, a substantial number of people will visit your web site based on printed business cards, billboards, or newsletter listings.
Unlike physical addresses that are located in geographic regions, such as counties and neighborhoods, web addresses are global.  People who look for physical addresses can sometimes get close and then look for familiar landmarks or ask directions.  People on the web who type one wrong letter will not find you.  If you move your web site to another computer, you can keep the same domain name.  So a domain name is more permanent than a physical address.
A domain name also gives your organization a sense of reputation, based on your having a permanent address.  Many sites provide free web addresses with long names such as http://geocities.com/theredwoods/~1493/index.html Besides finding you, most people more comfortable in dealing with a unique domain name, such as http://bakery.com or http://kidsclub.org
Would you feel comfortable in dealing with a business operating out of someone's living room or a rented warehouse, compared with a business operating on a major street? Web visitors are still wary of the changeable, free-for-all nature of the web, especially since you can't see what you're buying until you receive it.  Even when the order fulfillment is the downloading of electronic software, the reputation of the dealer is more important in the nebulous electronic world than in the real world.  Having a domain name gives your business a small sense of validity in the perception of customers.  Do you want people to come to you?
The majority of people will probably find your product or organization through search engines. Search engines are computer programs which sweep the web for pages, index the page addresses, and catalog them with other information so people can find it.  Getting listed on the search engines is a tedious and competitive process.  Search engines often give preference to web sites with their own domain names.