Slide size is important in PowerPoint because it determines the aspect, ratio and resolution of your presentation.

The aspect ratio is the proportion of the width and height of the slide, and it affects how your slides appear on different screens or devices.

To change the slide size, click on the design tab and then click on slide size.

There you can select a predefined size or enter your own dimensions using custom slide size.

You can choose from different slide sizes in PowerPoint, such as standard four by three, which is the most common aspect ratio for presentations as this is typically the ratio used for projectors wide screen 16 by 9 is also available.

However, this slide size is more commonly used for video production.

However, widescreen is increasingly being used for business presentations as this is a more modern aspect ratio.

And lastly, custom, which gives you a range of exercises, but also the flexibility to input your own specific measurements if needed.

You can also adjust the orientation of your slides to be portrait or landscape.

Changing the slide size can help you create presentations that fit your audience's needs and expectations.

One of the main questions to be asking yourself before starting a presentation is what device or screen is this going to be presented on? It's good to get as much information on the projector or device at the start as changing the size aspect ratio of your presentation once it's finished as possible.

but PowerPoint won't adjust all the components perfectly, and so further editing will be required if you do have to change the aspect ratio later on.