A runestone is typically a raised stone with a runic inscription, but the term can also be applied to inscriptions on boulders and on bedrock. The tradition of erecting runestones as a memorial to dead men began in the 4th century and lasted into the 12th century, but the majority of the extant runestones date from the late Viking Age. While most of these are located in Scandinavia, particularly Sweden, there are also scattered runestones in locations that were visited by Norsemen. Runestones were usually brightly coloured when erected, though this is no longer evident as the colour has worn off.

A rune is a letter in a set of related alphabets known as runic alphabets native to the Germanic peoples. Runes were used to write Germanic languages before they adopted the Latin alphabet, and for specialised purposes thereafter. In addition to representing a sound value, runes can be used to represent the concepts after which they are named (ideographs). Scholars refer to instances of the latter as Begriffsrunen. The Scandinavian variants are also known as fuþark, or futhark, these names derived from the first six letters of the script, ⟨ᚠ⟩, ⟨ᚢ⟩, ⟨ᚦ⟩, ⟨ᚨ⟩/⟨ᚬ⟩, ⟨ᚱ⟩, and ⟨ᚲ⟩/⟨ᚴ⟩, corresponding to the Latin letters ⟨f⟩, ⟨u⟩, ⟨þ⟩/⟨th⟩, ⟨a⟩, ⟨r⟩, and ⟨k⟩. The Anglo-Saxon variant is futhorc, or fuþorc, due to changes in Old English of the sounds represented by the fourth letter, ⟨ᚨ⟩/⟨ᚩ⟩.