At the time of writing, there are two core license acquisition models: direct licensing and indirect licensing. 

Direct licensing refers to when an organization makes a direct purchase, such as through Microsoft Admin Center.

Indirect licensing refers to when an organization makes a purchase through a partner or reseller agreement. There are currently six indirect licensing methods available to acquire Microsoft 365. They are as follows:

• Cloud Solution Provider (CSP): Organizations establish a billing relationship with a provider, who purchases on their behalf and sells the licenses to the customer.
• Microsoft Open (includes Open Value, Open Value Subscription, and Open License): The Open License program allows customers to buy licensing through a reseller, typically for smaller organizations (more than 5 seats and typically fewer than 500).
• Enterprise Agreement (EA): A program that is designed for larger organizations (more than 500 users or devices) and can include cloud services and software licenses together.
• Microsoft Products and Services Agreement (MPSA): A purchasing account structure designed for organizations that use product pools and groupings to determine the price of services. Organizations must have more than 250 users or devices.
• Services Provider License Agreement (SPLA): License structure designed for independent software vendors and service providers who want to license and host applications and services for customers.
• Select Plus: Select Plus is a purchasing mechanism targeted at large organizations with a number of affiliates who want to purchase as one entity. It is no longer available to commercial customers but is available for public sector customers.

Many Microsoft cloud services are calculated based on the number of users (commonly referred to as seats) that will be subscribing to a particular service or plan. Several key characteristics should be assessed when deciding which model is right for your organization:

• Minimum number of seats
• When you can make changes to the number of seats (either additions or removals)
• The cadence of the billing (annual, pay as you go, or some other contract mechanism)
• Which products or services are available under the licensing model
• Duration of the agreement

For the MS-900 exam, we'll highlight the structure and requirements of the Cloud Solution Provider (CSP) model.

The CSP program is designed for Microsoft Partners and Value-Added Resellers (VARs) as a way to develop long-lasting, holistic partnerships with customers. The CSP program has a wealth of tools available to help partners and VARs provide value to their customers.

When evaluating the CSP program against the aforementioned criteria, we're able to determine the following characteristics:

• Minimum of one seat.
• The number of seats that can be changed on a monthly basis.
• Billing cadence is "pay as you go."
• All Microsoft Online Services products are available.
• The agreement has a minimum duration of one year.

Licensing and acquisition costs are part of the Total Cost of Ownership (TCO) of any product or service (whether for on-premise or cloud services). In the next section, we'll examine more closely the case for cloud services by performing a cost-benefit analysis.