The fretless bass
The differences regarding body construction are similar to those of guitars. There are basses with solid wooden bodies and bolted or set-in necks. Semi-acoustic basses also add to the palette. Finally, neoteric materials such as graphite expand into modern bass construction.
The fretless bass is a special type of bass instrument. As with classical string instruments it doesn't have any frets. Playing such type of bass needs a lot of practice as well as good hearing because the correct notes have to be played in context to what is heard. While the normal frets have a proper grid for the twelve normal octave notes, the notes on a fretless instrument can be changed continuously, thus, even minor deviations can create horrible tonal clashes. Fretless basses have an awesome fundamental sound but they are not as suitable for beginners for the reasons mentioned above.
The variety of bass shapes developed parallel those of guitars. There are approved standard models and shapes here too. They often originate from brands such as Gibson or Fender and are now being manufactured either identically or in a slightly modified form by southeast Asian producers as well. One such bass classic is the Fender Jazz-bass, which is still being copied down to the smallest detail today.
Along with the approved types available in every price range there is a growing market for high-end products made by brands specializing in manufacturing luxurious electric basses in fancy wood types. The electronics in these instruments is almost invariably active which means that they feature a small built-in battery-powered preamp to enhance the weak pickup signals in advance. Of course fabulous bass sounds can be produced with this technology which requires an accordingly fabulous amp setup to best display these sounds - both available at fabulously high prices. Since winning the lottery is still a matter of luck we will focus on the more common bass types.
The upright bass
A further special type of electric bass is the so-called upright bass. It is a double bass which features the characteristics of an electric bass, if you like. As with the double bass, it is placed between the legs of the player and played either standing or sitting, but as a solid wooden instrument it needs to be electrically amplified. This type of bass is rarely used by rock bands - maybe because the player is forced to stay in a constant position on stage. But according to insiders, the EUB (electric upright bass) is currently gaining popularity and has been highly regarded by jazz or jazz-rock musicians for years.
In the 50s the German company Framus were already producing an electrically amplified double bass. Their competitors Clevinger were the first to make uprights a lasting success.