Strip concrete is the most common type of foundation. It involves filling trenches with concrete, adding blockwork on top and then building up from that. They are often necessary in areas of softer soils, like sand, because they spread out the load of the building over a greater area. They aren’t very suited to poor ground conditions, though, and they’re also low lying, so if you think your plot might be at a risk of future flooding, you might want to consider other options.
Also, once they get to below a depth of about 2 metres, strip concrete foundations start to become uneconomical. That much concrete is costly, and laying it at such a depth can start to become dangerous. At that stage, it’s worth considering a deeper kind of foundation.