What did letters marque allow private shop owners to do?

Letters of marque allowed private ship owners to capture enemy ships and their cargo legally, essentially authorizing them to act as privateers during wartime. This practice enabled these privateers to operate under the protection of their government, receiving a share of the spoils from successful captures. It was a way for nations to bolster their naval power without the expense of maintaining a large standing navy. Ultimately, letters of marque contributed to the economic and military strategies of the issuing country.