Advanced info on Unity's camera matrix

Greetings,

I'm trying to learn the main concepts used behind Unity camera, in particular its matrix and having a few doubts that afaik aren't answered within Unity documention:

1) Is Unity camera based on OpenGL camera? For example, can the OpenGL tutorial on cameras found here be applied in Unity? If yes, then when representing a ModelViewProjection matrix, in Unity we have:

 MVPmatrix = mainCamera.projectionMatrix * mainCamera.worldToCameraMatrix; 

where MVP is a 4x4 matrix, while in OpenGL is represented through the following code:

 MVPmatrix = projection * view * model; 

Why the differences between the two methods?

3) When multiplying the previously mentioned MVPmatrix with a given Vector3[4] type, are we doing a conversion to homogeneous coordinates?

2) If the answer to 1) was "no", where can I get additional information on Unity's camera matrix?