A sine wave, in its simplest form, is a wave that has a fixed frequency and wavelength and is very reminiscent of the pictures that most people have seen of waves with no sharp angles. A sawtooth wave, however, has ramps that drop or begin sharply, becoming similar to the teeth of a saw. It can be found in some music and graphics applications.
Most conventional waves of this type begin by building pressure upward gradually in a straight line, then have a sharp drop off in another straight line. The process then repeats itself. One can also act in reverse, however, slowly going down before a sharp up slope. This is known as a reverse or inverse sawtooth wave. Either way, these types of sine waves still look like a saw, with the teeth being pointing upward.
Like all sine waves, this type of wave is capable of producing sound. As one might suspect, the sharp points mean that the sound it produces will likely be very harsh, compared to the soft sounds of most waves. It should also be relatively clear, however.
This wave does have practical applications. It often forms the foundation for music synthesizers, for example, and as such, it is responsible for their unique sounds and contributes to their ability to producing the sounds of other instruments. These waves are especially valuable when replicating the sounds of string instruments.
The sawtooth wave can also be used in visual applications, but this is not as common as the synthesized uses. Through its electromagnetic properties, the wave can actually be used to manipulate groups of pixels, or the raster, on the screen. As a result, it can be a very important tool for certain types of monitors, such as the more traditional CRT units.
One way a sawtooth wave differs from its counterparts is in its level of symmetry. Simply put, there is none within the wave. While each wavelength may be the same, the gradual slope will always be longer than the sharp slope. This is part of the very important difference between the sawtooth and other types of sine waves.