Summer squash, also known as courgette or baby marrow, is a vining herbaceous plant whose fruit is harvested while the immature seeds and epicarp are still soft and edible. It is related to, but not identical to, marrow; when mature, its fruit may be called marrow.

Although courgettes are classified as a vegetable, they are technically a fruit because they contain seeds. They are members of the cucurbit plant family, along with squash and cucumbers. Courgettes come in a variety of shapes and sizes. A long, curly courgette known as 'tromboncino' or 'tromba' is an unusual variety. They are known as zucchini in North America and Australia, which is the Italian name for them. Courgettes are versatile and can be used in a variety of dishes.