NBA tends to run more isolation plays, whereas Euroleague teams likek to run continuous offenses until they find a reasonable scoring option.
Forwards in FIBA are usually more well-rounded and capable of hitting shots from 20'+ out. It's not uncommon for FIBA bigs to be able to drive to the hoop from the perimeter. A lot of forwards from Europe have been characterized as above-average passers.
NBA forwards are usually more specialized, and don't necessarily need to be able to have a mid- to long-range game and required to have a more polished and more physical inside scoring game.
The rules are different as well.
The 3 point line in the NBA is something like 22-23 feet. FIBA is about a 1 1/2 feet closer.
In the NBA, a player can't touch the ball if it's inside the cylinder, which is an invisible cylinder that reaches infinitely above the hoop. If it's touched, it is considered basket interference/goaltending and the offending team is penalized (no basket if offensive, basket counts if defensive).
In FIBA, the ball can be played (but not touched through the hoop from the bottom) as soon as the ball hits the rim.
NBA has an insane number of timeouts. 6 full timeouts in a game, plus 1 20-second timeout in each half. Timeouts can be called at any time by any player on the court or the coach, so long as that team has the ball.
FIBA, you are entitled to 2 timeouts in the first. 3 in the second half. All timeouts are 60-seconds and can only be called during a dead-ball and by the coach on the sidelines.
Substitutions can be made before, during, and after free throws in the NBA. In FIBA, substitutions can only be made before the free throws start and after, if the last shot of the set is made.
Lastly (that I can think of), jump ball situations in the NBA are handled by a jump ball (shocking), but in FIBA they are decided using alternating possessions.