Load bearing wall means that the load is supported by the wall, there is no column/beam to support the load. These walls must be strong enough for the purpose. Load-bearing walls are one of the earliest forms of construction. Usually the thickness of these walls is 9 inches or more.
In frame structures, there is a combination of beam and column to support the load. The load rests on the beam, the beam transfers the load to the column, which in turn transfer the load to the foundation. Frame structures are the modern and safe way of designing large structures.