I followed a tutorial on rigging a character but do not achieve the same results. Re watched the video many times and still cant figure it out why some bones stretch instead of rolling. Do i need to enable something for the bones that have connection option turned off?
The bones in an armature are almost like separate objects. If a bone is not connected to its parent bone or restricted in some way you can move it freely as you have shown.
When a bone is parented, there is an option to have it connected, when enabled, this prevents a bone from being moved out on its own, effectively only allowing rotation. With it disabled, you often only want to rotate the bone, instead of moving it. This also prevents a bone being positioned away from the parent bone as the legs are in your armature.
The simple way to prevent the movement you show is to enable the transform locks.
Constraints can also be used in some situations to control bone movements.
In your example armature, you could also add a hip bone that it connected to the spine and the leg, preventing the movement you show.