Hydraulic excavators are powerful machines used for digging and moving large amounts of earth and materials. They consist of a boom, arm, bucket, and a rotating cab, which allows for a wide range of motion. The hydraulic system uses fluid pressure to operate the various components, making it efficient for tasks like construction, mining, and landscaping. These excavators come in various sizes, from compact models for small jobs to large ones for heavy-duty work. They are often equipped with different attachments, such as buckets, breakers, or grapples, to perform specific tasks, enhancing their versatility on job sites.