A TMD file has no one-size-fits-all meaning, as its role is based on the software that created it rather than the extension itself, and `. Here's more on TMD document file check out our own web page. tmd` is used by multiple unrelated systems where the file usually serves as a reference descriptor that lists other files, their sizes, versions, and verification details, so it generally isn’t something end users should open or edit; a major example is within Sony’s PS3, PSP, and PS Vita platforms, where TMD stands for Title Metadata and holds identifiers, version info, size values, verification hashes, and permissions used by the console to validate content, stored next to PKG, CERT, SIG, or EDAT files and required for proper installation and operation.