It eliminates the session closing overheads inherent in the multisession method of adding data to a disk in more than one write. With packet writing, you can use your CD-R just like a hard drive. With packet writing, there is no need to open or close a session each time data is written, which means even the CD-R novice should be able to copy data to CD with relative ease. Packet writing allows higher performance data transfer. Packet writing has the advantage of not using large areas of disk space between sessions, as is now the case with multisession writing.
Packet writing is an alternative to writing entire tracks or disks.
Since it's possible to write packets that are small enough to fit entirely in the CD recorder's buffer, the risk of buffer underruns is eliminated. Each time data is added incrementally to a CD, the laser must power up and power down, and as a result, useless blocks of data may be recorded to disk. Link Blocks are simply the blocks before and after user data that may contain this useless data. A single instance of written user data along with its associated Link Blocks is called a packet. These blocks allow the CD recorder's clock to get in sync with the recording at hand, and for interleaved data to play out.