Foresta vs. bosco
In Italian, both foresta and bosco translate to forest in English, but they are not interchangeable. The main difference lies in the size, density, and wildness of the area they describe.
Foresta
B1The word foresta refers to a very large, vast, and often wild or untouched expanse of trees. It evokes a sense of immensity and primordial nature, similar to a jungle or a large national park. It's often used for famous, expansive forests.
La foresta Amazzonica è fondamentale per l'equilibrio del clima mondiale.
(The Amazon rainforest is fundamental for the balance of the world's climate.)
I protagonisti del film si sono persi in una fitta e oscura foresta.
(The movie's protagonists got lost in a dense and dark forest.)
La guardia forestale si occupa della protezione di questa vasta area.
(The forest ranger is in charge of protecting this vast area.)
In geografia abbiamo studiato le caratteristiche della foresta boreale.
(In geography we studied the characteristics of the boreal forest.)
Poche persone hanno mai esplorato il cuore di quella foresta.
(Few people have ever explored the heart of that forest.)
Bosco
A2The word bosco is the more common and general term. It describes a smaller, more familiar area of trees, equivalent to woods or a grove. It feels less intimidating and wild than a foresta and is often the place one might go for a walk, a picnic, or to forage for mushrooms.
Domenica andiamo a fare una passeggiata nel bosco dietro casa.
(On Sunday we are going for a walk in the woods behind the house.)
In autunno ci piace andare a raccogliere funghi e castagne nel bosco.
(In autumn we like to go pick mushrooms and chestnuts in the woods.)
Cappuccetto Rosso doveva attraversare il bosco per raggiungere la nonna.
(Little Red Riding Hood had to cross the woods to reach her grandmother.)
Hanno costruito una nuova casa ai margini di un piccolo bosco di pini.
(They built a new house on the edge of a small pine wood.)
Il sentiero si snoda attraverso un bosco di faggi secolari.
(The path winds through a wood of ancient beech trees.)
Summary
In essence, the key distinction is scale and wildness. A foresta is a vast, dense, and wild forest, often remote and untamed. A bosco is a smaller, more common area of woodland, what you would typically call the woods. You can think of a foresta as potentially containing many different boschi, but a bosco is just a single, smaller wooded area.