This character is a Other Symbol and is commonly used, that is, in no specific script. The character is also known as paper in Rock, Paper and Scissors game.
The glyph is not a composition. Its East Asian Width is wide. In bidirectional text it acts as Other Neutral. When changing direction it is not mirrored. U+270B prohibits a line break after it, if it’s followed by an emoji modifier.
The CLDR project calls this character “raised hand” for use in screen reading software. It assigns these additional labels, e.g. for search in emoji pickers: 5, five, hand, high, raised, stop.
This character is designated as an emoji. It will be rendered as colorful emoji on conforming platforms. To reduce it to a monochrome character, you can combine it with Variation Selector-15: ✋︎ The character can be changed in appearance, if it is followed by an emoji modifier. See the Emojipedia for more details on this character’s emoji properties.
The Wikipedia has the following information about this codepoint:
Raising hands is a gesture involving lifting either one or both arms above one's head, which has a number of possible meanings, depending on the context of the gesture.
The action of hand-raising is involved in a number of greeting hand gestures, such as waving, salutes, and high fives. The raised fist, an action used mostly in left-wing political endeavours and by oppressed minorities, is a symbol of defiance and solidarity. The Nazi salute is demonstrated by flattening the right hand, straightening the arm and raising it just above one's shoulder. A 'show of hands' is defined as a vote wherein people raise one hand to demonstrate their support for or opposition towards an idea.
Hand-raising is also involved in actions of other disciplines. One such discipline is yoga, which incorporates many poses with one or both arms extended into the air, such as Urdhva Vrikshasana, which translates to ‘raised hands pose’.