Salesforce provides a functionality to set the accessibility of record. We can set the record's accessibility by changing the Access Level, Access Levels are like Private, Read Only, Read/Write and Full Access. In Salesforce the most permissive level of access is used.

Here are the most share objects which support the following access levels:

Access Level	API Name	Description
Private	None	At this level the object will display/view only the owner/creator of that object and those users who are above of the record owner in the role hierarchy. Lower in role hierarchy can't see the object and this access level only applies to the AccountShare object.
Read Only	Read	At this level the specified user or group can only view the object.
Read/Write	Edit	At this level the specified user or group can view and edit the record.
Full Access	All	At this level the specified user or group can view, edit, transfer, share and delete the record.