This character is a Other Number and is commonly used, that is, in no specific script. The codepoint represents the digit1.
The glyph is a subscript version of the glyph Digit One. Its width in East Asian texts is determined by its context. It can be displayed wide or narrow. In bidirectional text it is written as European number from left to right. When changing direction it is not mirrored. If its East Asian Width is “narrow”, U+2081 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 Wikipedia has the following information about this codepoint:
1 (one, unit, unity) is a number, numeral, and glyph. It is the first and smallest positive integer of the infinite sequence of natural numbers. This fundamental property has led to its unique uses in other fields, ranging from science to sports, where it commonly denotes the first, leading, or top thing in a group. 1 is the unit of counting or measurement, a determiner for singular nouns, and a gender-neutral pronoun. Historically, the representation of 1 evolved from ancient Sumerian and Babylonian symbols to the modern Arabic numeral.
In mathematics, 1 is the multiplicative identity, meaning that any number multiplied by 1 equals the same number. 1 is by convention not considered a prime number. In digital technology, 1 represents the "on" state in binary code, the foundation of computing. Philosophically, 1 symbolizes the ultimate reality or source of existence in various traditions.