Magnetic tapes have been a major medium for recording music, video and data for decades. They include popular consumer products like compact cassettes and VHS video tapes, as well as professional reel-to-reel magnetic recording stock. Magnetic tape has several advantages, even when compared to digital media, but also has some important drawbacks.
One of the key advantages of magnetic tape is its capacity for holding data. Magnetic tape was the first medium able to hold a feature-length movie on a small, inexpensive device, thus enabling the home video market of the 1980s. In addition, compact cassettes can hold music on both sides, giving them a 90-minute total playing time, which is even greater than most CDs.
Magnetic tape is also easy to edit using a traditional linear-editing system. This can involve duplicating a portion of a tape to a master reel, or physically cutting the tape and attaching the desired portions together with glue, splicing cement or adhesive tape. Editing in this manner requires no special computer equipment and may be less expensive and/or easier to learn than nonlinear digital editing.
One of the disadvantages of magnetic tape is generation loss, which refers to the fact that each successive copy of a tape loses quality compared to the original. This can make it difficult to use magnetic tape for editing-intensive projects, or when extremely high fidelity is important. Digital media, on the other hand, can be copied and reproduced indefinitely with no visible or audible difference between the original and any of its copies.
Another problem with magnetic tape is its tendency to stretch out over time, causing the quality of the data to deteriorate. On old video tapes, this generally appears in the form of poor audio, and picture data can eventually suffer as well. Over time magnetic tape acquires a layer of magnetic debris from recording and playback heads, which may need to be cleaned periodically to continue functioning.
The mechanical complexity needed to use magnetic tape is another disadvantage of the medium. Items like cassette and VHS tapes include two separate reels, as well as a mechanism for exposing a small portion of the tape inside a player or recording device. Reel-to-reel tape players use multiple motors and moving parts, each of which is susceptible to mechanical failure. In the realm of digital media, flash-based memory uses no moving parts, thus eliminating this problem.