interference

Hello I was just wondering if interference is something to study for the physics part of the OAT. Such as double slit, singe slit interference, or diffraction grating.

Is interference tested on the physics portion of the OAT? Things like the double slit, single single slit, diffraction grating, and thin films? Thanks!

I had some questions on this topic: 1- Is diffraction the same as interference? 2- why does the slit size have to be comparable or smaller than the wavelength? and is it the case for single slit and double slit? Thanks a lot!