Accounts and contacts are collectively known as customers in CRM. Understanding how to create and manage these customers in CRM is essential, and necessary before tracking sales.
The account entity is one of the central components of a CRM system and is essential in managing customers that are organizations. Opportunities, sales, and service-related items for an organization can all be tracked by using the account entity.
According to MSDN, the account entity can be a parent to almost any other entity, including another account. An account can only have one parent account, but can have multiple child accounts and/or child contacts.