As Yooper already mentioned, prior to pitching the yeast, you should aerate/oxygenate the wort so that the yeast can reproduce... How you give them the oxygen is up to you. Some use the pour into primary, splashing like a mother. Others shake the living snot out of the fermenter before pitching. Then there's others that use a pure O2 setup and get more oxygen into the wort in <60 seconds than you could with extensive shaking, use of a pump (still with ambient air), running from a ball valve, etc. The pure O2 setup has extra benefits of being very little physical effort on our part, plus takes such a small amount of time. There is a limit to how much oxygen you can infuse into the wort without using pure O2. For most moderate gravity (and lower) brews, that's not an issue. Try to brew something bigger and you'll want more than you can get that way.
I've been using the pure O2 method for some time now and have been really enjoying it. I picked up a regulator with a flow meter (made for oxygen) that I should be able to use with my next batch. I simply need the fitting to connect it up to the tubing that runs to the air stone wand. Once I have that in place, I'll actually see how many liters per minute I'm sending into the wort. THEN I'll be able to properly oxygenate my batches to a higher level of precision. No more guessing about how much I'm giving it. :rockin: