A zester is a kitchen tool used to remove the outer zest of citrus fruits like lemons, limes, and oranges. It typically features a small, sharp blade or a series of tiny holes that scrape off the colorful outer layer of the fruit's peel without cutting into the bitter white pith underneath. This zest adds intense flavor and aroma to various dishes and beverages. Zesters come in different designs, including handheld versions and those integrated into multi-functional kitchen gadgets. They are popular among chefs and home cooks alike for enhancing the taste of desserts, marinades, and cocktails, making them a versatile addition to any kitchen.