A loop cut adds a ring of edges all the way around a mesh, so you get more detail in one band without touching the rest.
Drag a model to turn it.
An edge loopA chain of edges that circles the mesh and closes on itself, like a line of latitude.Adding loopsThe same cube with 1 to 4 loop cuts. Each cut splits every face it crosses.Sliding a loopA placed loop can slide along the faces around it, to sit exactly where detail is needed.Bending, 2 ringsThe orange line is the bend we want. With no rings between the ends, the tube can only lean as a straight shape.Bending, 10 ringsLoops along the length let it follow the curve. Arms and legs get extra loops at the joints for this reason.
In your tool
Run the loop cut tool (also called Insert Edge Loop, Swift Loop or Connect).
Hover an edge to preview the loop, and set how many to add.