Structure
Left and right nav bars may be pinned for permanent display, or they can float temporarily as overlays. Temporary nav drawers overlay the content canvas; whereas pinned nav panels are situated alongside or below the content canvas.
Screen size can determine whether a panel is pinned or an overlay. With sufficient space, a panel can be pinned and content adjusted responsively. With insufficient space, a panel has to be an overlay.
Left nav content is ideally navigation- or identity-based. Right-nav content should be secondary to the main content on a page.