Offset
Offset copies sketch geometry inward or outward by a distance: walls, clearances, margins and the inset pockets that follow an existing outline.
Fillet
A 2D fillet rounds the corner where two sketch edges meet: the edges are trimmed back and a tangent arc fills the gap.
Project
Project flattens 3D edges and faces — or the geometry of a previous sketch — onto the sketch plane. The projected curves are fixed reference geometry: the solver never moves them, they render as locked (green) geometry, and your sketch geometry can be constrained against them. It is how a feature follows the shape of what is already there.
Intersect
Intersect cuts the sketch plane through 3D faces and brings the section curves into the sketch. Like a projection, the result is fixed reference geometry: the solver never moves it, it renders as locked (green) geometry, and your sketch geometry can be constrained against it. Where Project flattens what you would see of a face from the sketch plane, Intersect gives you the true outline where the plane passes through it — the wall of a bore, the profile of a curved cavity, the section of a rib.
Copy
Copy duplicates sketch geometry along one or two directions or around a centre point. The copies take part in the same face-building step as the rest of the sketch, so a copied circle is a hole like the original.
Mirror
Mirror reflects sketch geometry across a line or an axis. Draw one half of a symmetric profile, mirror it, and the two halves join into one region.
Guides
Guides are construction geometry: drawn and constrained like everything else, visible in the viewport, but left out of the profile when the sketch becomes a face. Use them for layout circles, centre lines, mirror lines and anything you constrain against but do not want extruded.
Split
Split cuts a sketch edge in two at the point you click. The two pieces stay joined at the split point, which becomes a vertex you can drag, dimension or build a notch from. To remove part of an edge instead, use Trim.
Trim
Trim removes the part of a sketch edge you click: the stretch between the nearest crossings on either side of the click. It is how a circle drawn across an outline becomes a notch, or a line drawn past a corner is cut back to it. To cut an edge in two without removing anything, use Split.