An easement is a specific right to use property. A utility easement would be the right of the power, gas and water companies to individual properties to maintain and install power, water, gas and other utilities.
Utility easements are portions of an individual's property, as described by statute and/ or in the deed, that public utility company personnel have a right to access or transverse.
Power companies have utility easements to allow them to work on your land to provide for your safety and the general good. This can affect you in what you may plant or build on your property to insure it doesn't interfere with public utilities and access to them.
A utlity easement allows utility companies to come and work on your land in order to supply the utlities. For example, a water company can work on water lines.