Aperture: n. the opening in a photographic lens that admits the light.

True.  Measured in f-stops, aperture is the the focal measurement of how much light is allowed through the lens to the camera.  It gives photographers the ability to shoot in dim lighting without flash and it also allows the ability to increase or decrease depth of field.  Here is a picture that shows a variety of f-stops:

Now here's an example of some actual shots with different apertures:

f/1.4                                                     f/2.0                                                     f/4.0

f/8.0                                                      f/16                                                       f/22

ladeeda

my ride - 151 Photofetish by Capita, with Kelly green/white Cartel bindings by Burton. 

Here's the view off of my roof.  It's been hella cold since I moved and even when I took this shot on Good Friday it was like 20 degrees with the wind chill...

This image was created by autostitching 31 images together and then cropping a part off.  I wonder how a night shot would look???

image properties: 40mm, F/14, ISO 100

Why is everything ok one day and the next, one of my coworkers decide they want a different career path, or one gets fired or one decides to move to another position, all at once! Damn... work is gonna be crazy over the next several months... i'm screwed.