Bolso vs. bolsa vs. bolsillo

In Spanish, 'bolso', 'bolsa', and 'bolsillo' refer to different types of containers or pockets, and they are used in various contexts.

Bolso

A 'bolso' is a handbag or purse, typically carried by individuals (often women) to store personal items like wallets, phones, cosmetics, etc.
Ella siempre lleva un bolso grande al trabajo.
(She always carries a large handbag to work.)
Compré un bonito bolso de cuero en la tienda.
(I bought a nice leather purse at the store.)

Bolsa

'Bolsa' refers to a bag or sack used for carrying groceries, clothes, or other items. It can also mean a plastic or paper shopping bag.
Necesitamos una bolsa para llevar todas estas frutas.
(We need a bag to carry all these fruits.)
Me olvidé de traer la bolsa reutilizable al supermercado.
(I forgot to bring the reusable bag to the supermarket.)

Bolsillo

'Bolsillo' means pocket, typically a small compartment sewn into clothing where small items like keys, coins, and phones can be kept.
Tengo las llaves en el bolsillo de mi chaqueta.
(I have the keys in the pocket of my jacket.)
Encontré unos billetes en el bolsillo del pantalón viejo.
(I found some bills in the pocket of my old pants.)

Summary

In summary: 'Bolso' refers to a handbag or purse; 'bolsa' is a bag or sack; and 'bolsillo' is a pocket. These items serve different purposes and are used in various everyday contexts.