This character is a Other Letter and is mainly used in the Han script. The Unihan Database defines it as one; a, an; alone. Its Pīnyīn pronunciation is yī. The codepoint has the numeric value 1.
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. U+4E00 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:
Radical 1 or radical one (一部) meaning "one" is one of the 6 Kangxi radicals (214 radicals in total) composed of 1 stroke. It is the simplest Chinese character in the language due to consisting of only one line.
In the Kangxi Dictionary, there are 60 characters (out of 47,043) to be found under this radical.
一 is also the 1st indexing component in the Table of Indexing Chinese Character Components predominantly adopted by Simplified Chinese dictionaries published in mainland China.