When deciding to purchase an electric guitar, one of the biggest details about the guitar that a customer must consider, is the instrument's tonal quality. Each and every guitar that you play will have a slight variation in how it sounds compared to other guitars. No two guitars sound exactly alike, even if they're the same model. That's because there are so many different factors in the stages of a guitar's development that determine the tonal uniqueness. There are quite a few different factors that cause a guitar to sound a certain way. Factors such as the guitar's construction method, what tonal woods the guitar is composed of, what type of pickups the guitar has, and what type of amplifier is being used. The more often you play the guitar, the more easier these tonal differences will be to recognize as well.
One of the biggest game-changers of your guitar's tone is the amplifier that you use to project its sound. There are three main types of guitar amplifiers that are used today: tube amps, solid-state amps, and digital modeling amps. The tube amp uses the oldest form of technology, where the tone is created using glass tubes. Tube amps are generally more expensive, and the tubes are known to burn out after a long amount of years. However, the majority of guitar players prefer the sound of a tube-amp, due to its rich, distinct tone. Solid-state amps, which are the most common amps, use transistors and circuit boards instead of tubes. They're lighter and more affordable as well. Then, last but not least, there are digital modeling amps which generally have a large repertoir of guitar effects and tonal variations. Modeling amps are also quite affordable, and can sometimes mimic the sound of a tube amp decently well. When it comes to amplifiers, you generally get what you pay for. The more expensive the amp, and the higher the wattage, generally the better your guitar will sound.
The second biggest factor in determining your guitar's specific tone, is the type of pickups it uses. Pickups are basically magnets that pick up the vibrations of your guitar's strings, and send the signals of their vibration to your amp, thus creating an amplified sound of your strings. There are two main variants of a guitar pickup: the "single-coil" and the "humbucker". A single-coil pickup is composed of a single winding of a very thin wire around a magnetic poles, in order to create a magnet. A humbucker has two windings of one single wire around two poles next to each other, as opposed to one winding. These two poles cancel out each other and minimize the "humming" sound that can be heard from a single-coil when the volume is cranked. Humbuckers generally have a "thicker", more booming sound, while single-coils generally have sharper, thin but clear notes. Both types of pickups are often used by guitarists, and both are preferred for different reasons and genres of music. Preference is dependent on the person's personal preference.
Another big way a guitar's tone is affected, is by how the guitar is constructed. There are countless different construction combinations in building a guitar, which involve the guitar's neck joint construction, the type of guitar body, whether the guitar is hollow or solid, and whether the guitar has a flat or arched top. A Gibson arch-top electric guitar will definitely sound different from a Gibson Les Paul, because a Les Paul is a solid-bodied guitar, while an arch-top has a hollow construction. A guitar's neck joint construction method determines how much sustain the guitar will have, as well as how well each note will resonate. Also, a guitar's body thickness plays a small factor in whether the guitar will resonate more or less.
Finally, the most debated factor of a guitar's tone, is the guitar's tonal woods. Tonal woods are the types of wood that guitars and other instruments are typically made out of, that allow an instrument to resonate and balance tone well. Common woods used for guitar bodies and necks include maple, basswood, alder, mahogany, rosewood, ash, and ebony. There are also many other woods as well, many of which are variations, such as flamed maple and quilter maple. The reason why tone woods are so debated, is that many people will argue that woods don't affect an electric guitar's tone at all, since the amp does most of the work. However, they will claim that an acoustic guitar's tone is certainly affected by the tone woods that are used. Honestly, if it affects an acoustic guitar, it must affect an electric guitar, even if by a very small margin. There's a reason why Gibson puts so much effort into using the highest-quality mahogany and maple for its Les Pauls. So, there are two main categories of tone woods. There are "soft" woods and "hard" woods. Soft woods are woods like mahogany, that are porous and allow the guitar to have a good, resonant bass tone. Hard woods are woods like maple, that aren't porous, and allow for a brighter sound. The terms "hard" and "soft" for describing a wood's physical characteristics can be quite confusing, since there are many "soft" woods that are very hard in density. The terms don't necessarily mean that the wood is harder or softer, physically.
When choosing a guitar, it is important for a buyer to consider all of these characteristics. However, the best way to find the best tone, is to go to a local guitar store, and pick up a wide variety of guitars, and see what sounds are the most appealing. Every guitar sounds different, and some guitars sound shockingly good, despite looking ordinary in appearance.