This character is a Other Symbol and is commonly used, that is, in no specific script.
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+1F618 offers a line break opportunity at its position, except in some numeric contexts.
The CLDR project calls this character βface blowing a kissβ for use in screen reading software. It assigns these additional labels, e.g. for search in emoji pickers: adorbs, bae, blowing, face, flirt, heart, ily, kiss, love, lover, miss, muah, romantic, smooch, xoxo, you.
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: ποΈ See the Emojipedia for more details on this characterβs emoji properties.
On Youtube this character is sometimes wrongly displayed as U0001f618.
The Wikipedia has the following information about this codepoint:
An air kiss, blown kiss, or thrown kiss is a ritual or social gesture whose meaning is basically the same as that of many forms of kissing. The air kiss is a pretence of kissing: the lips are pursed as if kissing, but without actually touching the other person's body. Sometimes, the air kiss includes touching cheek-to-cheek. Also, the gesture may be accompanied by the mwah sound. The onomatopoeic word mwah (a representation of the sound of a kiss) has entered Webster's dictionary.
The character block Unicode 1F618 provides the "emoji face throwing a kiss π" to computer screens.