Solar cells, modules and panels

I've written about a solar module, so this time I'll write about how solar cells are related to solar modules. First of all, what's the difference?
The short answer is that a module is made up of cells that are electrically connected together. In an electrical circuit, each solar cell acts as a temporary battery that operates while the sun is shining on it. There are essentially two ways that cells can be connected together. A series connection has the cells all connected in a row, just like a flashlight can have batteries connected in a row. If a single battery has 1.5 volts, then 4 batteries in a row will have 4 x 1.5V = 6V where the batteries are all touching each other end to end and the external connections are made to one end of the first battery and the other end of the last battery. Likewise for solar cells. Very roughly, a solar cell has half a volt or a bit more. Surprisingly, this is true of most kinds of solar cells, whether thin film or crystalline silicon or any other material - this is by design, not coincidence, but I won't go into the reasons here (ok, it has to do with making the most efficient use of the solar spectrum). If the solar cells are series connected the total voltage of the system can be increased. A typical setup might be to string 24 cells together for an output of 24 x 0.5V = 12 volts.
There's another way to connect cells together. Instead of lining them up end to end, they can be connected in parallel by placing them in a row with the all positive terminals connected together and all the negative terminals connected together. The voltage of this assembly will be just that of a single cell. However, each cell contributes current and the currents will all add up. If you remember from my description of the solar module, the bigger it is, the more current it generates. Connecting cells in parallel is just as if a single cell got bigger.
To get both more voltage and more current, cells can be both parallel and series connected. A string of series connected cells can be parallel connected to other strings of series connected cells. In this way, cells can be assembled to produce a desired current and voltage. Just as a refresher, the electrical power output of a module is the voltage multiplied by the current and is measured in watts.
When you're in the solar store looking at solar panels, what you're seeing is a packaged module with a supporting frame and a little box of circuitry. The circuitry deals with compatibility issues when many panels are interconnected but not performing equally, such as when some panels are under full sun and some are shaded. Partial shading of solar installations can be a real problem, but I'm not going to discuss that this time. In fact, I think I'll stop here, now that I hope I've explained the relationship between solar cells, solar modules and solar panels.