Basic schematics question

Maybe I was a little harsh. As a refresher, AoE might be fine.

When I was in school, the text books were all pretty dry. Long on theory, short on applications. Best instructor I had was a retired Navy electrical engineer. His lectures were all about practical applications.
 
The + and - circles are where the board connects to the power jack. There is a pad marked + and a pad marked - on the board, near the center along the top edge. Those schematic symbols represent those pads.
How do the + and - circles relate to VCC in that diagram? Is VCC representing an output in that stage and then an input 4 times (R3, R6, R8 and Q1) in the top section of the schematic?
 
The + and - are the solder pads for the wires to the dc jack.

Vcc is approximately 9vDC that powers the circuit. The diode in between + and Vcc is to block reverse voltage, so other components in the circuit wouldn’t be damaged if you plugged in the wrong supply. I said approximately 9vDC because the diode will cause a very small voltage drop (I think around 0.2-0.3v) from the + to Vcc.
 
Think of all the VCC pins as having a trace from the power supply to those points, it’s just a lot easier and cleaner to make them pin points in the schematic.
 
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