The Unicode code point U+2764 identifies the heart symbol used for the Red Heart emoji before an optional variation selector is applied.
U+2764 is the hexadecimal code point for the Unicode character HEAVY BLACK HEART. When it is followed by variation selector-16, written U+FE0F, systems are instructed to prefer an emoji-style presentation, commonly displayed as a red heart. Without that selector, some contexts may show a text-style black heart instead.
This is why the visible emoji can involve more than one encoded code point. The heart itself and the presentation instruction are separate parts of the character sequence. Fonts and platforms still control the exact artwork, so the shape and color can vary slightly.
The symbol is often confused with other heart emoji, including Broken Heart, Two Hearts and Heart With Arrow. Those have different Unicode names and code points, even though all belong to the wider family of heart-related symbols.