I am going to fix up my deck. It looks old and beat down but I think it can be restored. I have been reading various things online about cleaning and sealing the deck in order to bring it back to greatness. Do I also need to sand it? Splinters are becoming more frequent and I want to do this right the first time.

The previous owners also put a red stain on it so figuring out the type of wood was difficult but it appears to be made of pine.

So, do I need to Sand it? Would I do anything different if it was Cedar (just out of curiosity)?

If it's making splinters, yes, you should sand it. That would be true for Cedar as well.

If you do it yourself, cost is not an object, then you can sand. It will takes many, many hours and the end product may still be dicey. I have done decks and restorations for 40 years and when they are this bad I recommend new lumber on top of the old joists.

Ballenger has a good point, sometimes the effort is not worth the end product. Replacement may make better sense.