A mechanical pencil is a writing instrument that uses a thin, replaceable lead core instead of traditional graphite. It features a mechanism that allows users to advance the lead as it wears down, providing a consistent line width. Mechanical pencils come in various sizes and styles, often with adjustable lead thickness for different writing or drawing needs. These pencils are popular among students, artists, and professionals due to their convenience and precision. Unlike regular pencils, which require sharpening, mechanical pencils can be used continuously without interruption. They are often made from durable materials, making them a long-lasting choice for everyday writing tasks.