An essential tool is a device or instrument that is crucial for performing a particular task, and without which the task would be impossible or extremely difficult to accomplish. It is an indispensable item that plays a vital role in achieving success in a given activity. Essential tools can vary depending on the context and purpose they are being used for, but generally speaking, they are items that have been specifically designed to make work easier, more efficient, or more effective. In short, essential tools are those that cannot be overlooked or neglected when it comes to getting a job done right.