Meaning
The letters abc inside a square, the label for typing Latin letters. It stands for the alphabet, spelling and letters in general, without saying upper or lower case.
Teachers and parents use it for alphabet lessons and spelling games, and learners use it for language practice: “Learning a new language, back to 🔤 basics” It also fits word games and font talk. For strictly capital or small letters, 🔠 and 🔡 are more specific.