A shepherd is someone who looks after sheep. Shepherds usually take the sheep out into fields so that they can graze (eat the grass). In the same way, someone who looks after cows is called a “cowherd”. A "swineherd" looks after pigs and a "goatherd" looks after goats. A herd is a group of animals. "Herding" can also mean making a herd of animals go to another place. A female shepherd is called a “shepherdess”.
Many years ago, when most people lived in the country, shepherding was very common. Sheep were kept for their milk, meat, and especially their wool. We know that there were shepherds in some parts of the world thousands of years ago.
The shepherd’s job was to make sure the sheep were safe and they were not eaten by wolves or other wild animals.