IAM is a good acronym for Identity and Access Management - it suggests an assertion of identity: "I am".

The term Identity Management (IDM) is used across industry to represent the processes, technologies and protocols that manage digital identities across systems and organisations.

IAM extends the scope of IDM to include how and in what circumstances digital identities may be used.

A digital identity is the electronic equivalent of physical identifiers such as a passport, driving licence, certificate or membership card. These ‘hard’ identities will probably be managed (issued and maintained) by many different organisations.  Digital identities are managed and used in a similar manner.