Radiation diagram
There are many parameters, but two that I believe are most important for your led project  .  first we will concentrate on the radiation diagram.

The various states in the diagram each represent one configuration of the led. from this point (0.1)of view,  that small ellipse which creates magnificent light effects. and ellipse right is the relative value perspective, the lower-left portion is an luminous instensity. most led is three-dimensional. so led radiation diagram

in a much more robust way than you can understand multi-Dimensional Space Description of led. which gives you the freedom to choose the led that suits your led project needs.