This character is a Math Symbol and is commonly used, that is, in no specific script. The character is also known as summation sign.
The glyph is not a composition. Its width in East Asian texts is determined by its context. It can be displayed wide or narrow. In bidirectional text it acts as Other Neutral. When changing direction it is mirrored. If its East Asian Width is “narrow”, U+2211 forms a word with similar characters, which prevents a line break inside it. Otherwise it allows line breaks around it, except in some numeric contexts. The glyph can be confused with one other glyph.
The CLDR project calls this character “n-ary summation” for use in screen reading software. It assigns these additional labels, e.g. for search in emoji pickers: mathematics, summation.
The Wikipedia has the following information about this codepoint:
Sigma ( SIG-mə; uppercase Σ, lowercase σ, lowercase in word-final position ς; Greek: σίγμα) is the eighteenth letter of the Greek alphabet. In the system of Greek numerals, it has a value of 200. In general mathematics, uppercase Σ is used as an operator for summation. When used at the end of a letter-case word (one that does not use all caps), the final form (ς) is used. In Ὀδυσσεύς (Odysseus), for example, the two lowercase sigmas (σ) in the center of the name are distinct from the word-final sigma (ς) at the end. The Latin letter S derives from sigma while the Cyrillic letter Es derives from a lunate form of this letter.