Morphologically speaking, logos are divided into three different categories according to their composition (icons, typography, or both combined together). These categories are: logotypes, isotypes, and isologotypes. Each of them has its own advantages and disadvantages. In this section, we will make a distinction between the three of them depending on which one is better for each particular case.

Logotype: it is made up only of typography, and it is usually the name of the company it represents. Because of this, it requires a representative typography able to transmit a message. A logotype has two communicative channels: the verbal and the non-verbal. The verbal is that of words and their phonic substance (the name of the company and its sound); the non-verbal, that of symbolic meanings given to the letters, themselves drawings. For example, by means of a process called “transformation into curves”, designers can mold letters as if they were drawings. Thus, not only will each letter represent a different phoneme, but they will also mean something else according to their shape, colors and dimensions. A clear example would be to mold an “s” so that it resembles a snake. As a result, the “s” will represent both its corresponding phoneme and a serpent. That is why typography is so important. Moreover, there are certain kinds of typography which can suggest tradition, the family, antiquity, or exactly the opposite instead. The logotype is easy to remember because it is made up of words. Nevertheless, it is not, as we will see, the most memorable type of logo.

Isotype: it consists only of an icon or image (no typography included). This type of logo requires an image or drawing able to transmit information –in a clear, explicit way if possible–. As, unlike the logotype, the isotype has no words at all, the choice of an image to be the exclusive representation of a company must be made with great care. Nike’s famous logo clearly suggests speed and motion, so words are unnecessary. However, this is not easy to achieve, especially if we consider that it is a golden rule never to include too many graphic elements so the design is easy to remember. The question is, then, how to create a drawing that is clear enough to be understood without any words, and at the same time simple enough to be easily remembered. Even so, the isotype is, thanks to its characteristics, the most memorable type of logo –studies show that remembering images is easier than remembering words.

Isologotype: it consists of a representative image, together with typography (often the name of the company it represents). As it is a combination of the two previous ones, both their advantages and disadvantages converge on it. One disadvantage is that, since it includes more constituent parts, it is slightly hard to remember. However, it has a great advantage: it is very easy to understand. An effective image accompanied by a word or a short phrase is concise in addition to perfectly clear, so there is no room for misunderstanding.