There's no other instrument with as much presence and cultural identity as the guitar. Virtually everyone is familiar with tons of different guitar sounds, from intense metal shredding to soft and jaunty acoustic folk music. And behind all those iconic guitar tones are great sets of strings. Just like a saxophonist changes reeds from time to time or a drummer replaces sticks, putting new strings on your guitar every so often is an important part of owning and playing one.
Getting to grips with how chords are formed gives you a basic introduction to music theory and helps you understand the ways you can alter them to create more interesting sounds. All chords are built from certain notes in scales. The C major scale is the easiest, because it just runs C, D, E, F, G, A and B. These notes are numbered (usually using Roman numerals) in that order, from one (I) to seven (VII).

The loud, amplified sound and sonic power of the electric guitar played through a guitar amp has played a key role in the development of blues and rock music, both as an accompaniment instrument (playing riffs and chords) and performing guitar solos, and in many rock subgenres, notably heavy metal music and punk rock. The electric guitar has had a major influence on popular culture. The guitar is used in a wide variety of musical genres worldwide. It is recognized as a primary instrument in genres such as blues, bluegrass, country, flamenco, folk, jazz, jota, mariachi, metal, punk, reggae, rock, soul, and many forms of pop.
First, you need to determine what type of guitar you have - acoustic nylon, acoustic steel string, or electric. You want to be sure to use the correct strings for your particular guitar. Acoustic guitars that require nylon strings, such as classical, flamenco and some folk guitars, generally have lighter tops, or soundboards, with less internal bracing than those found on steel-string acoustics, and stand the risk of serious damage if fitted with steel strings. Steel-string acoustics are designed to withstand the added stress that steel strings exert on the top, bridge, nut and neck, and won't sound very good with nylon strings, if they even fit. Electric guitar strings must be made of ferromagnetic metals like steel and nickel, so they can interact with the magnetic pickups, while acoustic-electric guitars typically use a different type of pickup which senses vibrations from the bridge, so acoustic strings may just have a steel core wound with a phosphor bronze alloy wrap for bright tone. Guitars with whammy bars might require a few extra steps to keep everything stable, so check your manufacturer's instructions or look for online videos.
Unlike many string instruments which use a bow to create a sound, guitars are played by plucking or strumming the strings on the instrument, which vibrate to create a sound. Chords are played when the guitarist holds their fingers down on more than one individual string to change its length, which in turn changes the frequency of the vibration created - in other words, it creates a different note. Performers often use guitar tabs, rather than sheet music, when learning music: this acts as a kind of 'map' to teach guitarists where to put their fingers on the strings.