Packet writing allows users to create, modify, and delete files and directories on demand without the need to burn a whole disc.
Because of this, the available space on a non-rewritable medium using packet writing technology will decrease every time its content is modified.
Due to the characteristics of optical rewritable media such as CD-RWs and DVD-RWs, the ability of data sectors to hold their contents diminishes when changing them frequently (since re-crystallized alloy de-crystallizes).
[1] Packet writing is most popularly implemented by Microsoft since Windows Vista, where it is referred to as the Live File System.
Software implementing packet writing includes: This computer hardware article is a stub.