Call-by-Object is also known as Call-by-Sharing or Call-by-Object-Sharing.
The semantics of call-by-Object differ from call-by-reference in that assignments to function arguments within the function aren't visible to the caller. However since the function has access to the same object as the caller (no copy is made), mutations to those objects within the function are visible to the caller, which differs from call-by-value semantics.
Although this term has widespread usage in the Python community, identical semantics in other languages such as Java and Visual Basic are often described as call-by-value, where the value is implied to be a reference to the object.