This character is a Other Letter and is mainly used in the Katakana script.
The glyph is not a composition. Its East Asian Width is wide. In bidirectional text it is written from left to right. When changing direction it is not mirrored. This katakana joins with other adjacent katakana to form a word. U+30CB offers a line break opportunity at its position, except in some numeric contexts. The glyph can be confused with one other glyph.
The Wikipedia has the following information about this codepoint:
に, in hiragana, or ニ in katakana, is one of the Japanese kana, which each represent one mora. The hiragana is written in three strokes, while the katakana in two. Both represent /ni/ although for phonological reasons, the actual pronunciation is [ɲi].
Notably, the katakana (ニ) is functionally identical to the kanji for two (二), pronounced the same way, and written similarly.
に is used as a particle, with a similar function to the English "to", "in", "at", or "by":