A Shared Object file, often referred to as a Flash cookie or Local Shared Object (LSO), is a data file used by Adobe Flash Player and Adobe AIR applications to store information on a user's computer. This information can include user preferences, game progress, application settings, or other data that the application needs to remember between sessions. Unlike standard HTTP cookies, Shared Objects can store significantly more data (up to 100KB by default) and are not subject to the same privacy controls as HTTP cookies. They are stored in a hidden location on the user's hard drive, making them less transparent to the user. Shared Objects can be used for legitimate purposes, such as saving game progress or remembering user preferences, but they can also be used for tracking user behavior without their explicit consent. Because of privacy concerns, modern browsers and Flash Player settings allow users to manage and delete Shared Objects. The file format itself is a binary format specific to Adobe Flash and AIR.