I come across these two phrases a lot on here:

1) Bet to keep the worse hand in and make the better hand fold
2) Don't slowplay

What I'm not sure i get is where the line is drawn between the two. In some ways i feel they contradict each other. For example if I bet just enough to keep the wrse hand in and they improve to beat me on the turn or the river, didn't I solw play it?

I seem to be more successful when I try to take the pot down early, even if I am betting worse hands out. I often get burned when the weaker hand pays against the odds but then improves to beat me.

Can someone shed some light on this for me?