Guitar Bridge - Tremolo System

A bridge is a device for supporting the strings on a stringed instrument and transmitting the vibration of those strings to some other structural component of the instrument in order to transfer the sound to the surrounding air.
The bridge is placed perpendicular to the strings and larger surface (which are roughly parallel to one another) with the tension of the strings pressing down on the bridge and thus on the larger surface beneath it.

Bridges for electric guitars can be divided into two main groups, "tremolo" and "non-tremolo" (also called hardtail).

Tremolo bridges
Tremolo bridges usually need to be suspended in some way, which reduces contact. Most tremolo designs today use a group of springs in the guitar body, which oppose the tension of the strings. Some players feel that the vibration of the springs affects resonance in a way that makes the guitar sound better; others disagree. Naturally, it all depends on personal preference and the musical style of the individual player. There are two kinds of tremolos bridge:

Non-Locking Tremolo
Non-locking (or vintage) tremolos are the bridges found on all guitars manufactured prior to the advent of the Floyd Rose locking tremolo in the late 1970s and many (typically cheaper) guitars manufactured thereafter. For many playing styles, vintage tremolos are a good choice because they are easy to use and maintain and have very few parts. Some people feel that they can also provide a better degree of sound transfer, especially with tailpiece type tremolos such as the Bigsby.

However, "Synchronized Tremolo" type found on the Fender Stratocaster is balanced against a set of screws in much the same manner as a locking tremolo and offers little improvement in the way of sounds transfer. This picture is an example of vintage tremolo bridge which usually used in old fender stratocaster

Given that this type of tremolo is installed on solid body guitars the degree to which sound transfer affects the sound that the instrument produces is minimal. Also, keeping a guitar with a non-locking tremolo in tune can be difficult. The most common types of non-locking tremolos are the "Synchronized Tremolo" type and an almost endless stream of copies and also the Bigsby type although that type has largely fallen out of favour. The modern tremolo bridge that can be found nowadays

Locking Tremolo
Another type of tremolo is the locking tremolo. These bridges have a sort of vise in each saddle which clamps the string into place (usually with an Allen Key). The end of the string has a clamp, which holds the string in place, stopping it from slipping. This is especially useful for songs that require tapping or heavy/hard playing styles. Once set up for tuning stability, locking tremolos are very good. However, their fulcrum points offer extremely minute contact with the body, which may disturb sound transfer.

Around 1979, the locking tremolo was invented by Floyd D. Rose. The locking tremolo became highly popular among 1980s heavy metal guitarists due to its extremely wide range of variation and tuning stability.

The original Floyd Rose system was similar to the Fender synchronized tremolo, but with a number of extra mechanisms. The first to be added and most obvious is a locking plate on the head nut, tightened with a hex key to fix the strings at this point after tuning. This provides extra tuning stability, particularly during use of the tremolo arm, but as an unwanted side effect it also prevents further adjustment of the pitch using the machine heads.

This is an original floyd rose tremolo

and this is the pro version