If you want to put your video files online using HTML5 then it's recommended to have three different formats for a full browser support. Those formats are mp4, ogv and webm.
Some installations or settings changes require you to restart your computer. In most cases you don't need to actually reboot it, you only need to restart the explorer.exe process.
If you are on a certain data plan on your mobile provider, and don't want to exceed it, you can set data usage warning and a limit which can help you save some of your money.
Themes, background images, and layouts are a good way for you to customize your presentation and tailor it to a particular audience. In this lesson you will learn how you can easily set a custom wallpaper, or use a theme that Google Present offers.