Visual Studio Project vs. Solution

Being new to VS, how may I think of these two concepts, what is the difference?

I find some missing information in the other answers (at least for people who come from other IDEs like, say, Eclipse) . To say that a solution is a container for projects is only part of the thing. The conceptual feature of a VS project (what determines its 'granularity') is that one project produces one output: typically an executable or a library (dll). So, if you are going to code three executables that uses related code, you'll create one solution and at least three projects - probably more.

A solution is a container for projects, and tracks dependencies between projects.

Just to come up with a metaphor..

A solution is like a house, a project like a room. Each room provides a piece of functionality whereas the house, a container of rooms, provides the means to link the rooms together and organize them appropriately.

Kind of corny but I made it up on the fly, so bear with me :)

It doesn't help that Visual Studio seems to make things more confusing. "New Project" actually creates a new SOLUTION containing a project. "Open Project" actually opens a solution containing one (or many) project. (The file menu says "Open Project/Solution" but it really is opening solutions. There is no "Close Project" only "Close Solution" which is accurate.

So, in VS you are always working within a solution. Many solutions contain only one project and newer developers are likely to think of them as the same thing. However you can add other projects into a solution.