A TS file is a text file that contains TypeScript code, an open source programming language developed by Microsoft. TypeScript is a superset of ECMAScript 2015, which is a superset of JavaScript. It is used for developing medium- to large-scale JavaScript applications for server-side or client-side execution. TS files are similar to JavaScript .JS files.

TypeScript was made public in late 2012 and was developed for the purpose of easing the development of components in complex JavaScript code. It is a statically typed superset of JavaScript that compiles to plain JavaScript, which can be run on web browsers, in Node.js, or in any JavaScript engine supporting ECMAScript 3 or later. The language extension comes with all the features of JavaScript while adding features such as static type checking, interfaces, type erasure, enumerated type, and namespaces.

Video stream format used for storing video on a DVD; compresses video data using standard MEPG-2 (.MPEG) video compression.

TS files are often saved as multiple files on a DVD, i.e. "moviename1.ts," "moviename2.ts," "moviename3.ts," etc. They can be played back by various software DVD players and video editing tools.