Badge is a type of Push Notification available in Windows 8. It is displayed over the top of a tile. Badges are small icons that are shown in the lower right corner of a tile. The tile can either be a default tile or a tile with a notification. A badge can display either a number from 1-99 or a status glyph. Now it is to be noticed that 99 is the largest number to be displayed as a badge. Even if you provide a number larger than 99, it will show badge notification as 99 only.You can have a full overview about number badges and glyph badges from here.