Despite the rules of basketball not changing when playing outside, there are many factors that influence how the game is played. The weather, court conditions, and double rims are all major differences from the typical indoor version of the game.
Most outdoor basketball hoops have a double rim style of hoop. The reasons for this are to increase durability from wear and tear of continuous usage. A hoop that is constantly being dunked on needs extra stability.
Double rims make shooting the ball much more difficult, which can be detrimental but also beneficial. In the short term, it may be annoying because few bounces will go the shooter's way. The upside is that this will force players to have more arc on their shots and be more accurate, thus training them to be better at shooting.
The main difference between indoor and outdoor basketball is the aspect that humans have little control over. If it is raining, snowing, or too windy, playing outdoors could be a miserable experience. Even when it is sunny out, the brightness could affect a player's ability to see the ball from certain spots on the court.
The direct effect of these weather conditions is the impact on the court. Even if it is not currently raining, the court may still be wet making it difficult to play without slipping. The court also needs constant maintenance to ensure the paved surface is not cracking or being overrun by weeds.
Some basketballs are specifically designed for outside basketball with increased durability and grip.