This is one of the most popular and easier of knots available.
It gets its name from the shape formed by the knotted rope, it is especially practical as a stopper knot.
With the rope end, take it back along itself and under itself, then wrap over, thus forming a loop,pass the end through the loop and dress the knot pulling the end to tighten the knot.
A slight variation is a figure of eight loop or bight, carried out in the same way, form a loop and tie in the same way as above, go back on itself, pass under, then over and then through the loop and dress the knot. This will form a bight, loop, for attaching things to. Such as rings, tools or karabinas etc.
I often use both of the above especially the figure of eight loop, especially when tying things onto my trailer or roof rack of the car.
The
"truckers hitch" is a good knot to learn also, which can be explained another day, but the two examples above are by far the easiest to learn.