No, the complete assemblies for front and rear are different; the front hub assembly includes the steering knuckle:

Front:

Rear:

 

The front bearing is typically pressed out of and back into the the existing steering knuckle. Some front bearing kits will include a new hub\wheel flange but you can often reuse those as well unless the bearing went so bad that it damaged the hub. As others pointed out, you can also buy a complete knuckle assembly with bearing already pressed in.

 

And if you have ABS, make sure you get a bearing / hub assembly with the magnetic ring for the ABS system.