A Linear Bounded Automaton (LBA) is a type of theoretical computing machine that operates within a limited amount of tape space. It is a variant of the Turing machine, where the tape length is restricted to a linear function of the input size. This means that the LBA can only use a portion of the tape proportional to the length of the input, making it more constrained than a standard Turing machine. LBAs are used to recognize a specific class of languages known as context-sensitive languages. These languages are more complex than context-free languages but less complex than those recognized by unrestricted Turing machines. The LBA's limitations make it a useful model for understanding computational complexity and the boundaries of what can be computed with limited resources.