< b="" />Answer:
A group of people is referred to as a crowd.

< b="" />Explanation:
- A crowd is a term used to describe a large group of people gathered together in a particular place.
- Crowds can form for various reasons, such as attending events, protests, or simply being in a public space.
- The term "crowd" implies a sense of a large number of individuals who are typically close to each other.
- Crowds can be seen in various settings, including stadiums, concert venues, shopping malls, and city streets.

< b="" />Comparison with other options:
While the other options listed (herd, swarm, flock) are also used to describe groups of living beings, they are more commonly associated with specific types of animals or insects.

- Herd: A herd is generally used to refer to a group of large animals, such as cattle, horses, or elephants, that live and move together.
- Swarm: A swarm typically refers to a large group of insects, such as bees or locusts, that move together in a coordinated manner.
- Flock: A flock is often used to describe a group of birds, such as ducks, geese, or pigeons, that fly together or move together on the ground.

< b="" />Conclusion:
Out of the given options, "crowd" is the correct term to refer to a group of people. The other options are more commonly used to describe groups of animals or insects.