A more thorough explanation:

Definition: A block is a defined area within a city or town that is surrounded by streets. It can also refer to a group of things that are bought or sold together as a unit.

Example 1: I live three blocks away from the park.

Example 2: She bought a block of tickets for the concert.

These examples illustrate the two different meanings of the word "block." In the first example, "block" refers to a defined area within a city or town. The speaker is saying that they live three blocks away from the park, meaning that they live three defined areas away from the park. In the second example, "block" refers to a group of things that are bought or sold together as a unit. The speaker bought a block of tickets for the concert, meaning that they bought a group of tickets that were sold together as a unit.