Access Management (AM) is a security discipline that provides access to authorised users to enter particular resources. It also prevents non-authorised users from accessing the resources. Thus the goal of Access Management is to unify the security mechanisms that take place when a user is accessing a specific system or functionality. Single Sign-On (SSO) is sometimes considered to be a part of Access Management.
Example
New employee is hired. He needs access to various resources like databases, servers or applications and is also added to various access groups according to his job role. An Access Management system makes sure he gets the access: on time and to needed systems. Thanks to AM it is determined what is available there for him: what information or funcionality he sees what what parts of the system he can work with.
Access Management is frequently called as identity Management, but these terms are not identical: Identity Management is about managing the attributes related to the user such as username, fullName, location, telephone number or authorizations while Access Management is about evaluating the attributes based on policies and making yes and no decisions.