Yes, this question is in reference to these kits because you will need to both of these tasks. The cat was probably left out of the bag there because no, cleaning and sanitizing are not the same thing. You should be performing the cleaning process first and this merely consists of removing any oils, minerals or soils from the equipment that you have. If you need to, you can use acids but it may or may not be necessary.
After you clean all your equipment, you then need to sanitize it and this is why it is nice when sanitizer is included. When you sanitize your equipment, it will reduce the number of bacteria that will be present for your next brew. But, you should never rinse after sanitizing as this can reintroduce the microorganisms that were just killed.