It is very helpful to give your companies different types, so you classify them and know directly what kind of company it is. You can differentiate them in customer, supplier and providers for example.
You can create company types in settings / company.
Here you add as many company types as you want, by clicking on the "+ Add Type" button. It will open a new pop-up window where you can name the type and chose a nice little icon for that.
After you saved the type, you can select it when you are creating a new company. For that you just have to create a company and add the new type as described in the article.