Runes are the letters in a set of related alphabets, known as runic rows, runic alphabets or futharks (also, see futhark vs runic alphabet), native to the Germanic peoples. Runes were primarily used to represent a sound value (a phoneme) but they were also used to represent the concepts after which they are named (ideographic runes). Runology is the academic study of the runic alphabets, runic inscriptions, runestones, and their history. Runology forms a specialised branch of Germanic philology.
The earliest secure runic inscriptions date from at latest AD 150, with a possible earlier inscription dating to AD 50 and Tacitus's possible description of rune use from around AD 98. The Hole Runestone dates from between BC 50 and AD 275. Runes were generally replaced by the Latin alphabet as the cultures that had used runes underwent Christianisation, by approximately AD 700 in central Europe and 1100 in northern Europe. However, the use of runes persisted for specialized purposes beyond this period. Up until the early 20th century, runes were still used in rural Sweden for decorative purposes in Dalarna and on runic calendars.