High-capacity transmission lines are used to carry electricity long distances.
Transformers near the generation facility increase the voltage for more efficient transmission over long distances. These voltages are dangerous, which is why transmission lines are located on high towers.
As it gets closer to where it will be used, electricity is routed through transformers at distribution substations, which lower the voltage for safety in populated areas.
Often the electricity is lowered further via neighborhood transformers before passing into members’ service lines. Those voltages typically are 120/240 volts for homes and 480 volts for business and industry.
Transmission lines operate somewhat like interstate freeways that move large volumes of traffic. The lower-capacity distribution lines operate like streets that crisscross communities and neighborhoods. When freeways get congested, everything slows down.
In a similar way, transmission lines get congested and electricity cannot flow as reliably from the source of generation to your home or business.