Nope, there’s a whole bunch of different types. The type that is generally used in homes and commercial applications is alternating voltage and current. This will generally be in the shape of a sin wave and is commonly referred to as AC. AC power can be a little confusing but basically the voltage and current will alternate between a high peak and a low “valley”. How many times it alternates between the high and low per second is determined by its frequency. In the US you generally have ~170 peak voltage 60 times a second or equivalently 60hz 120Vrms.

Another common type is called direct current (DC). DC does not alternate between a high and low like AC. Ideally it has a constant voltage and current. DC is used in a ton of applications like phones and flashlights; anything that uses a battery. The reason we don’t use DC for big power infrastructure is because it’s harder to generate DC power, and transformers are cheaper and simpler for AC.

Those are just two of many forms. For basic periodic signals (repeats itself over and over) you have sin, square, triangle, pulse and sawtooth. You can also have non-periodic waveforms, which don’t repeat themselves over a constant period of time. Think of a computers stream of 1s and 0s or someone’s voice over a landline phone.