Logo
The following terms are often used interchangeably but they actually all have different meanings.
Signature / Logo
Contains the mark and the logotype or either one. It represents the company or an individual.
Logotype
Contains the word or words that determine the company.
Mark
An identifiable symbol that represents a company or individual.
Emblem
A design that is used to represent anĀ idea, or an individual
Trademark
Is a name or symbol that represents a company or product/service and is legally registered.
What we consider to be a logo is actually a signature. The word logo was originally derived from logotype.
Logotype
The company name.
Pictorial Mark

A pictorial mark is a recognizable image that has a literal meaning. It can appear with the name of the company or without.
Abstract Mark
An abstract mark is an abstract symbol. It can appear with the name of the company or without.
Monogram

A monogram uses one or more letters, often the initials of the name.