What is a compressor? An air compressor is a machine that increases the amount of air in a particular space. By packing in the air, the air pressure is increased which creates a force that is useful for a variety of purposes, from industrial and manufacturing to commercial and personal purposes. Air compressors are versatile and vital components of any factory or workshop. They’ve become smaller and less bulky in recent years, making them more usable in various work situations. Air compressors are a testament to human ingenuity. It’s important to understand how they work so you can choose the right air compressor for your project.