“show” turns on representations for objects and selections.

show [ representation [, selection ]]

representation = lines, spheres, mesh, ribbon, cartoon, sticks, dots, surface, labels, extent, nonbonded, nb_spheres, slice, extent, slice, dashes, angles, dihedrals, cgo, cell, callback, or everything

selection = string: a selection-expression or name-pattern

show 
show ribbon 
show lines, (name ca or name c or name n) 

With no arguments, “show” alone turns on lines for all bonds and nonbonded for all atoms in all molecular objects.

hide | enable | disable | cmd.show | commands

Core Commands, Representations, Atom Selections