Filtration question

[Fox]

I picked up a protein skimmer for my new tank setup which I thought was going to act as my filter for the tank but now I feel as though I misunderstood what it does. Will I also require a filter as well as the skimmer?

I do have a HOB and a submersible (canister?) filter I have been using in my freshwater tank that I upgraded, so I can get new media for them if I need to...but I just wondering if the skimmer is enough for the 33 gal or if I should be using one of the others as well.

I will have live rock with soft corals and fish in due time if that helps with the answer...I hope this post made sense...any info would be appreciated!

Cheers!