The Spanish guitar is acoustic. This means that it forms the sound completely on its own. It is primarily used for classical and Spanish music as flamenco. The main difference between this and other types of guitar, is the width of the neck. The wide fingerboard provide great distance between the strings and makes it therefore a very useful guitar for beginners. A Spanish guitar is fitted with nylon strings that give it a soft tone.
The western guitar is also acoustic. The Western guitar is in contrast to the Spanish guitar fitted with steel strings, giving it a clear and more penetrating tone.
It is ideal for chord play with a pick. However, it is not an ideal beginning guitar since the the fretboard is narrower and the strings harder for your fingers to press down.
The electric guitar produces virtually no sound on its own. It uses small mounted microphones to pick up string vibrations. These vibrations are fed through a cable and an amplifier in order to finally come out of a speaker as sound. It has a narrow fingerboard, which can make it difficult for beginners to position the fingers properly. In turn, the strings are easy to press down, which is a big plus for beginners.
A semi-acoustic guitar is as the name suggests, a mixture of an acoustic and an electric guitar. It has a hollow body and a sound hole as the acoustic guitar, but is also fitted with pickups (microphones), so that the sound can be amplified electrically. This type of instrument is widely used as jazz guitar.