In Minecraft, you can see everything around you, like blocks, mobs, items, and much more. Similarly, mobs and other entities can also detect you and your movement. This is one of the main game mechanics that help A.I. powered mobs look at you or detect you from far away. This is because your in-game is completely visible.
However, there are ways to vanish your character visually completely. This can help you sneak around hostile mobs without them detecting and attacking. Though most experienced players hardly use this technique, at least in single-player worlds, those of you who are beginners must know precisely how to become invisible in Minecraft.
