If your group is on a LAN then split the database into a back end that
contains all the data (normally the tables) and a front end that contains
everything else. Access has a wizard to do this for you Tools>Database
Utilities>Database Splitter.
The Back End should be in a shared networked folder for which your users
have full read write delete etc. permissions and you should supply a copy of
the front end for each client PC.
Each of the front ends should be linked to the tables on the back end
Tools>Database Utilities>Linked Table Manager.
Sharing an Access database over a WAN is not recommended.
The above assumes that each PC has a copy of Microsoft Access. If not you
need to buy the developer tools to distibute the front end with a run time
version of Access.
HTH