Why is a capacitor called a condenser?

A capacitor is sometimes called a condenser because of its ability to store or “condense” electric charge.

• When a voltage is applied across the two plates of a capacitor, opposite charges accumulate on the plates, creating an electric field.
• This storage of electrical energy in the form of separated charges is similar to how a liquid condenser collects and stores water vapor.
• Historically, when capacitors were first invented, scientists referred to them as condensers because they “condensed” or held electric charge for later use in circuits.

In short: A capacitor is called a condenser because it condenses (stores) electrical charge between its plates.