What does the ground connection mean?

[littlemal]

What does the ground connection mean? I'm new to this whole portable building.

[A.J. Franzman]

In most of these projects, ground is the negative power supply return connection, which is common to all of the circuits. It is the reference level from which all other voltages are measured.

In other electronice devices (such as your computer), there are also "negative" voltage connections which are considered as "below" ground level. Everything is relative, so this is all just a matter of point-of-view. Just remember that "ground" is not always the most negative voltage level, though for our purposes here it usually is.

[marshallh]

Ground is basically a common point, or wire where all negative leads are connected together. That's it. For example, you can hook your battery negative wire, your screen negative and your console negative up to the same wire/connection.