An Interpretation Please...Old School vs New School Poker

[Nalapoint1]

Overhead discussion at table by two well known players.
"he is a very good old school player.If he ever learns how to play new school,watch out".

What is the difference between old and new school poker?

I ask this because I was playing at 15/30 LHE.I was second oldest at table. 1 man was mid 60s and all others were less than 30. I am mid 40s. As I am leaving with $2500 profit in 2 hours the older guy stands up shakes my hand and says "you play pretty good old school poker. you might want to try new school and see how that works for you". This was several months ago and I didnt give it much thought. As always Thank You for sincere responses>