What are o-type or b-type spectral classes?

Stars come in different types, just like people have different personalities, some are loud and bright, others are quiet and cool.

Imagine you're at a party with two kinds of friends: the ones who always turn on the lights and sing loudly (o-type stars), and the ones who are still fun but not as flashy (b-type stars).

O-type stars are like the life of the party, super hot, super bright, and often have a blue or white color. They’re the biggest and loudest in the star world.

B-type stars are a little more laid-back. Still cool and bright, but not as extreme as o-type stars. They might be blue-white instead of pure blue, like wearing a slightly dimmer party light.

These types help astronomers know how old or big a star is, just by looking at its color and brightness, like reading a label on a toy box to know what's inside!