Diamonds symbolize keyframes on the timeline. 

The Track To constraint rotates its owner to point it in the direction of the target object.

Pressing “i”, while the mouse cursor hovers over a parameter, inserts a keyframe at the location of the playhead.

Pictures that define the starting and end points of a smooth transition are called keyframes.

To parent one object to another select the child and then parent to be and

Selecting an object and pressing "h"

ALT+h

Pictures that smooth out the transition between keyframes are called

FPS stands for