The Younger Futhark, also called Scandinavian runes, is a runic alphabet

Runic alphabet

The runic alphabets are a set of related alphabets using letters known as runes to write various Germanic languages before the adoption of the Latin alphabet and for specialized purposes thereafter...

, a reduced form of the Elder Futhark

Elder Futhark

The Elder Futhark is the oldest form of the runic alphabet, used by Germanic tribes for Northwest Germanic and Migration period Germanic dialects of the 2nd to 8th centuries for inscriptions on artifacts such as jewellery, amulets, tools, weapons and runestones...

, consisting of only 16 characters, in use from ca. 800 CE. The reduction, paradoxically, happened at the same time as phonetic changes led to a greater number of different phonemes in the spoken language, when Proto-Norse evolved into Old Norse.

Thus, the language included distinct sounds and minimal pair

Minimal pair

In phonology, minimal pairs are pairs of words or phrases in a particular language, which differ in only one phonological element, such as a phone, phoneme, toneme or chroneme and have distinct meanings...

s which were not separate in writing.