---
title: What are watts and what are they used for? | Holaluz
description: Discover what a watt is, how this unit of measurement works and why it is essential for understanding and optimising your home electricity consumption.
---

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# What are watts?

![Laura Benitez - Social Media Specialist en Holaluz](https://blog.holaluz.com/hs-fs/hubfs/laura%20benitez.webp?width=48&height=48&name=laura%20benitez.webp)

 Laura Benitez - Social Media Specialist en Holaluz

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We explain the definition of watt and why it is useful to understand this unit of measurement: discover all the answers to what is a watt, what the watt unit means in electricity and much more!

![What are watts?](https://blog.holaluz.com/hs-fs/hubfs/%C2%BFQu%C3%A9%20son%20los%20Watts%20o%20Vatios.jpg?width=747&height=347&name=%C2%BFQu%C3%A9%20son%20los%20Watts%20o%20Vatios.jpg)

When we look at our [electricity bill](https://blog.holaluz.com/entender-la-factura-de-la-luz-parte-i?hsLang=en), an electricity offer or search for an electrical appliance, we constantly see the symbols W, kW and MW. We know they refer to the unit of measurement known as the watt. But do we really know **what a watt is** and how watts are used in electricity?

## **What is the origin of the watt?**

The term **watt** is named after the engineer and mathematician **James Watt** (1736-1819), a key figure in the development of the steam engine, which, as you know, played an essential role in the generation of electrical energy.

## **What is the difference between watts and vatios?**

There is no technical difference: both refer to the same unit of power. “Watt” is the English term, while “vatio” is the Spanish term.

## **Watts and electrical energy**

We cannot understand **watts** separately from **electrical energy**, which is the capacity of a device to operate using a certain amount of “**fuel**”. Electrical energy is caused by the movement of electric charges inside **conductive materials**. This energy mainly produces three effects: light, heat and magnetism.

To understand what a watt is, you need to know that the watt is the unit used to represent electrical power. It indicates the rate at which electrical energy can be transformed. This unit, accepted in the International System of Units (SI) in 1889, is represented by the symbol W. So, **what is the equivalence of a watt?** It is equal to 1 joule per second (1 J/s). **And what is a joule?** The joule is the unit used to quantify the amount of energy used. In other words, if 1 joule is consumed per second, 1 watt of electrical power is being consumed. Put simply: 1 watt in joules equals 1 joule of electrical energy per second.

**What is the relationship between the watt and electricity?**

Want to know more about what a watt is? In electricity, watts indicate the amount of power generated when an electric current of 1 ampere flows with a potential difference of 1 volt. This is where voltage in volts and electric current in amperes also come into play. Low-power electrical devices can therefore be defined by their watts, while **higher electrical power** is usually expressed in **kilowatts (kW)**, equal to 1,000 watts, or **megawatts (MW)**, equal to one million watts. The idea is similar to grams, kilograms and tonnes.

When we want to know how much an electrical appliance consumes, it is common to confuse **watts** with **amperes**. They are not the same! This is the difference between a watt and an ampere: power in watts is the real power consumed by the device, while amperes show the “apparent power” and are mainly used to size cables correctly and avoid short circuits. That is why electricity consumption in watts and the electrical power of appliances are important data when assessing electrical appliance consumption and choosing [your contracted power](https://blog.holaluz.com/potencia-contratada-la-guia-definitiva?hsLang=en) in kW, avoiding the activation of the ICP.

Did you know that part of this is also reflected in your electricity bill? Yes, because it is quite common to confuse the kW, or kilowatts, of contracted power installed in your home with the **kWh of energy** consumed that you actually use. The first has a fixed cost and the second is variable, depending on your consumption. To understand your electricity bill, kW and kWh are not the same: the important thing is to distinguish between them and know what you are paying for in each case.

 

And if you want information about the price of electricity, you can find it at the following link.[Electricity price today](https://www.holaluz.com/en/electricity/electricity-price-today/)

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