While a material is being created it is inside the ingest process. When it is done it ends up in either status DONE or status FAILED. Failed of course means that the ingest process failed. A material that is DONE has passed the ingest process and it can be either active or inactive. Active means that it's in use, inactive means that it's not in use.
The default behaviour is that when a new version of a material is DONE it will replace the previous version (if there is one). The new material will be activated and the previously active material will be disabled. This behaviour can be changed per organisation unit using config. Currently this has to be done by a platform administrator.
The simple case which is the default behaviour is that there will only be one active material at a time, a new material will replace an old one.
All materials will be using the profile
default so profiles are not really relevant.
If you want to activate a previously inactivated material you can activate it using the customer portal. Note that you also have to inactivate the newest material.
The first slightly more complex thing you can do is to have multiple materials as active but you have different validity periods. This way you can for instance plan a change of material to be used in advance. If you set validity for material version 1 between 2021-01-01 - 2021-03-31 and validity period for material version 2 between 2021-03-31 - 2022-01-01 version 2 will take over 31/3. A different way of doing this is to keep version 1 with no validity period and add just a valid from date for version 2 to 2021-03-31. Before 2021-03-31 only version 1 is valid and will be in use. After 31/3 both materials are valid but version 2 will be used since it has a higher version number (will be picked first).
A more complex way of using multiple active materials is to use profiles. Then you can have multiple active materials with the same validity period but they are used for different users. See Material Profiles for more information.