What I learned...
Symbols and logos are also known as marks (or trademarks). Both symbols and logos need to be simple and easily recognized. They are representing a company so the symbol or logo needs to show that it is connected to that certain company through a memorable, simple, and timeless design.
A Logo
A logo is a word (or words) in type that identify a brand, company, group, or project. It can be a unique way to promote and it also makes it easier to recognize the company, brand, etc.
A Symbol
A symbol is a mark that has no type in it. It is used to identify an agency, corporation, or institution. It is also another unique and simple way to give a quick impact. There are many key factors in creating an effective symbol. It should be clean and have a good flow. To make your symbol memorable, it needs to be simple and have heavy marks, that way it stands out.