This is a red heart, the emoji version of heart symbol.
❤ generally means love, but it can also mean like, romance, affection or support to the one you care about. This emoji is used very frequently to express love, especially during Valentine's Day. Or you can just use it as a decoration in your text. Don't confuse it with
♥️ Heart Suit, which will be darker in color. Similar emojis:
🧡💛💚💙💜🤎🖤🤍❣