When something evolves, it changes, or develops over time, like your taste in music and clothes, which evolve as you get older.
Evolve comes from the Latin word ēvolvere, "to unroll," the perfect image to keep in mind when thinking of this verb. When something is unrolling or unraveling, it is doing so gradually, not all at once. Evolve describes a development that is taking its time to reach its final destination. Think change with a speed limit. Your taste in music evolved from the nursery rhymes you loved as a little kid to whatever you like today. Even places can evolve, like the old-fashioned coffee shops that evolved into Internet cafes as people began to bring their laptops with them.