Linear interpolation (LERP) is how you smoothly move from one value to another — perfect for animation, movement, blending, and UI transitions.
Fun wrinkle: if you’re interpolating directions around a sphere, straight-line lerp can cut through the middle and look wrong. That’s why we use SLERP (spherical lerp) for rotations.
Also: quaternions can interpolate nicely with similar math, and it somehow feels like wizardry the first time it works.