Phosphor bronze strings have a warmer sound with a smooth (if somewhat understated) high end response. This makes them a great fit for genres that benefit from a mellower tone, like a lot of folk or finger-style work. These strings pair well with smaller bodied guitars, though many musicians who play more relaxed genres prefer these strings on larger bodied instruments as well.
Though they may not be as exciting of a topic as instruments or amplifiers, choosing the right type of strings for your guitar is incredibly important. Guitar strings have different responses and different feels, and when the right type of string is used it’s a huge asset to your playing. Likewise, when the wrong type of string is used it can be incredibly detrimental.
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.