Quick question about stat blocks

[Iracus]

Hi everyone,

I am preparing to run my groups first session of RotRL so I have just been reading through the book. Aside from the beginners box, this is pretty much my first time playing pathfinder and GMing it. I am come across a confusing stat that I was hoping someone could clear up. What exactly does the following mean, specifically the +8/+3? I know the rest it is just those numbers that are confusing me.

Melee: mwk short sword +8/+3 (1d6+1/19-20)

[LazarX]

it means that the person is a high level character that makes two iterative attacks on a full attack round; the first at +8 and the second at +3. the totals figure in BAB and any other relevant bonuses, strength, etc.

If the person hits they do 1d6+1 points of damage and they threaten a critical on a die roll of 19 to 20.

If they make only one attack. (i.e. they had to make a move action to close) they roll at the first value, +8.