Photography is something that the majority of people are into these days. Every phone has a camera so it’s easy to get into it. Some people want to take their knowledge a bit further and perhaps, pick up a real camera. The Bokeh Simulator and Depth of Field Calculator will help you understand some key concepts a bit better.
The concept in this case would be depth of field. There’s a ton of reading out there about this and picking up a camera and just fiddling with it might teach you some things but not everything. For people who really want to understand cameras, this little site gives you a hands on way to experiment with the concept so you can get a better understanding of it before you start snapping pictures.
The website set up is fairly in depth. It lets you change aperture, sensor size, distance of your subject (a blonde cartoon character), framing, etc. The idea is to get you used to making changes while understanding what they mean so that you can capture better pictures. Give it a whirl for free.