Logotype, commonly know as a logo, is a design, a graphic representation/image/trademark symbolizing one's organization. Designed for instant identification, a logo can appear on company letterhead, advertising material and signs as an emblem by way of which the organization can easily be recognized.
Originating in the 19th century, after a surge in industrial manufacturing that led to an increase in output, global distribution, and the commencement of competition, logos were created to differentiate between products within the same industry. Emblems or symbols were included on products, packages and labels so buyers could easily recognize the product they preferred. Logos revolutionized the advertising world.
There was a time when only affluent organizations could afford their own crest, emblem or logo. They were, in some cases, a very detailed drawing with many objects. Cost was not an issue and more was considered better. Then, flags were used due to their larger format. They were visible from the craft fields and from long distances.
Today, successful companies continue to say that "simpler is better". Especially when the world is advancing so rapidly, you have less and less time to impress your customers. Logo designs, now, are very stylish yet remain conservative, which makes them eye-catching and easier for the brain to memorize.
The most crucial aspect of logo selection is the logo concept. You must first determine what your logo should say about your company. You may come up with an image related to a business like a house for real estate or a car for a car dealer, or your logo could be just an abstract image representing the company's philosophy, for example, a pyramid or a blocky image for a stable, trustworthy company. A very dynamic image with orbits and swooshes, sparks, or particles might be suitable for a very young, modern, high tech company.
Not all businesses, though, can be easily associated with any particular image. For example, a programming company doesn't have many images to associate with (except a computer). In this situation, it would be recommended to concentrate on an abstract image and to represent the feel of the company's business rather than coming up with a specific image. Companies that deal with more than one business should have a more generic image, but the logo can still be made to look technological by implementing some straight lines in combination with curves, or more corporate with more proportional, symmetrical, geometrical shapes.
As a result of the expense involved in changing a logo, a "good" logo shouldn't be too trendy, but ideally last many years before needing a redesign. You need to ask yourself if the design will be relevant in 5 or 10 years.
Once a company has established itself with a specific look, feel and image, it becomes more and more difficult to change as time goes by. Some companies have enjoyed success without ever having to change their logo design. Kentucky Fried Chicken has used Colonel Sanders in their logo since the company was founded in 1952. Aside from some updates on their marketing front, Nike would be another good example (the Nike swoosh). Pepsi took a risk in the mid 1990s by drastically changing their image and logo but did so with success. However, it could have resulted in commercial suicide. If you'll remember, in the 1980s Coca-cola changed their brand image to Coke. Pepsi then took over top seat in the market shortly thereafter. Creating a logo that can appeal to customers and consumers throughout the ages is important, considering that there will always be a risk involved with change.