File extensions

[JudyJones]

I am familiar with Access file extensions .mdb and .ldb. Someone asked me about the extensions .mdw and .bak that I am not sure about. The .bak sounds as if if would be for a backup file. I think they are using a database they purchased that was created with Access. Can anyone provide me with the purpose of files with these extensions?

[HansV]

The .bak extension is indeed for a backup copy of a file.

The .mdw extension is for so-called workgroup information files. They are used if you apply user-level security to an Access database. The .mdw file contains the names of the users and of the user groups and their memberships.
By default, Access uses a workgroup information file named System.mdw. You can, however, create new ones yourself, each with its own set of users and groups.

See Understanding the role of workgroup information files in Access security for more info.

[JudyJones]

Thanks for your quick response. I will pass it along to the person asking about this.