The Unicode block covering U+1F600 through U+1F64F is called Emoticons.
This block contains many familiar face emoji, including Grinning Face, Face with Tears of Joy, Winking Face, and other expressive characters. Unicode block names describe ranges of code points; they are not always identical to the everyday labels people use for individual emoji.
The Emoticons block was added as part of Unicode’s effort to encode pictographic symbols for interoperable digital text. Emoji are spread across several Unicode blocks, so not every emoji character is located in Emoticons. Animals, food, transport, flags, and body-related symbols appear in other ranges.
The range is hexadecimal, meaning the numbers use base 16. U+1F600 is the first code point in the block and U+1F64F is the last. A frequent mistake is calling the whole range “faces”; that is an informal description, whereas Emoticons is the formal block name.