"People" is the basic plural. If you're not sure which to use, then you'll be safer with "people". While "persons" is also plural, it suggests that we still focus on them as individuals.

Technically they have the same meaning, but in everyday-English "persons" sounds more formal and is usually used in the justice system, for example "persons in question". It is much more common to say "people" when speaking regularly.

We use "persons" to mean 2 or more individuals in a group. For example: "There are 3 Chinese persons in my class." We use "people" to mean many individuals in a group. For example: "The Chinese people are nice, hard working people." I hope this helps! Good luck with your English studies!