1- Artefacts. These describe any overt, visible, describable aspects of the organisation. Think things like branding and logos, office design, dress code, policies and tools. Things that you can see.
2- Espoused values. This is how people would describe the organisation, in current or aspirational terms. These include missions, goals, value statements, and social contracts.
3- Underlying assumptions. These are unconscious, unspoken, hard to articulate elements of the organisation, particularly from within.