The CMMI-Dev specification defines a requirement as:
(1) A condition or capability needed by a user to solve a problem or achieve an objective.
(2) A condition or capability that must be met or possessed by a product or product component to satisfy a contract, standard, specification, or other formally imposed documents.
(3) A documented representation of a condition or capability as in (1) or (2).
There are two Process Areas related to requirements, Requirements Development and Requirements Management.

Requirements Development (Level 3)
• SG 1 Develop Customer Requirements
– SP 1.1 Elicit Needs
– SP 1.2 Develop the Customer Requirements
• SG 2 Develop Product Requirements
– SP 2.1 Establish Product and Product Component Requirements
– SP 2.2 Allocate Product Component Requirements
– SP 2.3 Identify Interface Requirements
• SG 3 Analyze and Validate Requirements
– SP 3.1 Establish Operational Concepts and Scenarios
– SP 3.2 Establish a Definition of Required Functionality
– SP 3.3 Analyze Requirements
– SP 3.4 Analyze Requirements to Achieve Balance
– SP 3.5 Validate Requirements
Requirements Management (Level 2)
• SG 1 Manage Requirements
– SP 1.1 Obtain an Understanding of Requirements
– SP 1.2 Obtain Commitment to Requirements
– SP 1.3 Manage Requirements Changes
– SP 1.4 Maintain Bidirectional Traceability of Requirements
– SP 1.5 Identify Inconsistencies Between Project Work and Requirements

As you can see, the Specific Goals and Specific Practices are quite high level. Therefore, there are a number of processes that could satisfy the criteria. The key point is that the CMMI describes the areas of a process that should be examined. In subsequent articles I will examine how various processes satisfy the letter and the spirit of the CMMI requirements process areas.