Sensory receptors are special cells that responsible for our senses. There are four main types of sensory receptors.
Chemoreceptors sense chemicals, they allow us to taste and smell the particles in the air and in our food/drink.
Thermoreceptors sense temperature, they allow us to feel when things are hot and cold.
Mechanoreceptors sense pressure, they allow us to know when we are being touched or touching. They also sense vibrations and allow our ears to hear.
Photoreceptors or electromagnetic receptors sense light, they allow us to see.