Let's look at some of the components inside.

• The CPU is under the rounded black thing in the lower-left corner. That black thing is a fan, for cooling.
• Memory boards just north of that. We'll see them up close later.
• "power supply" on the right side. Note that this is accessible from the outside of the back of the case; that's where the power cord goes in. Digital electronic components generally require DC current at lower voltages than what you get from an electrical outlet in the wall; the "power supply" is basically a transformer.

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