Custom Event's are events that can be used to invoke a program function. This can be found in the variables panel by selecting a variable and enabling the 'Invokes the Function?' option and then selecting "custom event".
Start
This Custom event fires off the function as soon as the object is loaded.
Typically paired with "world" so the funciton can run as soon as the graphic is loaded.
Timer
This custom event triggers everytime the timer goes off
curVal
This custom event would run anytime the curVal changed in any way.
initialize
This event would run on any component, and it would fire when the component is loaded. This is a good way to load things