Party Model. Its important to note that this strength of this model resides in the idea that a Party can have many Accounts. Example: Company "A" be a Vendor to you in which they provide services. They can also be a Customer as well as a Partner to you. Each role the have with you results in an Account in which track sales, purchases, entitlements, transactions, etc... relating to that role. Accounts are used heavily by companies and is a critical component in your enterprise model.
Note 1: This model shows a Authentication Provider Account which follows a push for "Claim Based Authentication" technique for cloud based user logins.
Note 2: You will notice that the Account Contact Point Entity has a suggested Primary Key of Account ID, Party ID, Contact ID in which Party ID is BOLD. Party ID is an example of key folding in which the Party ID from Contact Point folds into Party ID from the Account Contact Entity. I personally like to call this a data harmonic. Hope that helps you understanding some advanced modeling techniques that are demonstrated in this model.
Please see (Baseline Conceptual Models Commentary) for further details on what conceptual models are to be used for.