LMB

LMB is an acronym that can refer to several things depending on context. The most common meaning is the left mouse button, the primary input button on a standard computer mouse.

In user interfaces, a left-click—pressing and releasing the LMB—is used to select items, activate controls, or initiate drag-and-drop operations. Double-clicking with the left mouse button typically opens files, folders, or applications, or executes a default action, depending on the operating system and software. The left mouse button’s behavior is usually paired with the right mouse button, which commonly opens a context menu or offers alternative actions.

Aside from computing, LMB can stand for different terms in various fields, including organizations, projects, or terminology specific to a discipline. Because the intended meaning is highly context-dependent, the abbreviation is usually clarified by the surrounding text or by consulting a domain-specific reference.