Similar words
balón
balón specifically means a bigger sports ball; bola is a more generic round object or sphere, like a "bola de nieve," a snowball.
Similar in other languages
French
boule
boule is the French word for the same thing — both mean "ball."
Practice
1 What does bola mean?
ball
2 Fill the gap: La ___ rodó por el suelo.
Full sentence: La bola rodó por el suelo. (The ball rolled on the floor.)
3 Which fingerprint chart matches bola?
bola: neutral register, common frequency, general domain, neutral connotation.