A more thorough explanation:

EXTRAMURAL POWERS

Extramural powers refer to the authority that a municipality has to exercise its powers outside of its corporate limits.

• A city council may have the power to regulate traffic on a state highway that runs through the city limits.
• A municipality may have the power to provide emergency services to neighboring communities.

These examples illustrate how a municipality can exercise its powers beyond its boundaries. In the first example, the city council is using its extramural powers to regulate traffic on a state highway that passes through the city. In the second example, the municipality is using its extramural powers to provide emergency services to neighboring communities that may not have the resources to do so themselves.