This tutorial explains how to pass arrays to shaders in Unity. This feature has been present for a long time, but is mostly undocumented. Unity 5.4.0 Beta 1 will introduce a proper API to pass arrays to shaders; this technique however will work with any previous version.
If you are using Unity 5.4+, please refer to the Arrays & Shaders in Unity 5.4+ tutorial.
Part 1, Part 2, Part 3, Part 4, Part 5
We can safely say that Unity3D has made game development easier for a lot of people. Something where it still has a long way to go is, with no doubt, shader coding. Often surrounded by mystery, a shader is a program specifically made to run on a GPU. It is, ultimately, what draws the triangles of your 3D models. Learning how to code shaders is essential if you want to give a special look to your game. Unity3D also uses them for postprocessing, making them essential for 2D games as well. This series of posts will gently introduce you to shader coding, and is oriented to developers with little to no knowledge about shaders.
The diagram below loosely represents the three different entities which plays a role in the rendering workflow of Unity3D: