What tool is primarily used for leveling and plumbing?

The tool that is primarily used for leveling and plumbing is the level. A level is designed to help determine whether a surface is horizontal (level) or vertical (plumb). It typically features a bubble vial or laser technology that indicates when the tool is in alignment with gravity. This capability makes it essential in construction and carpentry to ensure accuracy in the installation of fixtures, framing, and other structural elements.

The other tools mentioned serve different purposes. An impulse sprinkler is used for watering irrigation systems, a junction block is associated with electrical connections, and an increment borer is utilized in forestry for measuring tree growth. Each of these tools is specialized for its respective task and does not serve the function of leveling or plumbing.