Accounts are very similar to contacts because they work similarly.
As you can see on the follow image, the account list is displayed like the contact list even though the information provided is not exactly the same.
In a nutshell, an account is simply a company. Since a company is made of several people (employees, representatives, executives), an account can contain several contacts.
An account card displays basic information about a company, but it can also display custom profiling fields that you can configure according to your needs.
In the following example, there is only a single contact, but if several contacts had the same account name, they would all be visible here. The account card also displays the company's address on Google Maps.