The photo above was taken with a very high numbered “f-stop”, which apparently is described as a “narrow aperture”. The hole made by the blades through which the camera receives light is small, or narrow. f/29 is quite narrow.
The exposure time was 1/3 of a second, which was noticeably long when I took the photo. I was worried that I’d be too shaky to get a clear photo, but it seems okay. I was in aperture mode on the camera, so the time value was automatically decided for me. It needed to be so long because the amount of light that can get through the narrow slot isn’t enough at shorter periods.
You’ll notice though that the sign is in focus, but you can also see some people in the background. Not clearly, but you can see them. You can contrast this with the following photo I took a moment before.
Here the aperture is much bigger (the hole is wider). You’ll note that you can’t see the people at all in this photograph. They’re just blurs in the background.
Since the sensor can get more light to it through the wide aperture, the shutter doesn’t need to be open for nearly as long. This time the exposure time was much faster. You can see that there’s not a lot of blur in the sign this time, since I didn’t have time to shake the camera.