The neck grille or sensor mesh was the part of the neck section of the Dalek casing which served to cover the Dalek mutant within. It was supported by neck rings. (PROSE: Prisoner of the Daleks, Engines of War)
Typically, the neck grilles of most Daleks were coloured black. (TV: The Daleks et al.) However, the white Imperial Daleks created by Davros were distinct in that they had golden neck grilles with white neck rings. (TV: Revelation of the Daleks, Remembrance of the Daleks)
Assuming the role of controller of the Dalek-Humans, Dalek Caan was connected to the military computer of the Cult of Skaro's Transgenic Laboratory via numerous tubes and wires which were connected to the neck grille of his grating section. When the Dalek-Humans rebelled against the Daleks, Caan used his connection to kill them all remotely. Confronted by the Tenth Doctor, Caan abandoned his post at the laboratory via an emergency temporal shift. (TV: Evolution of the Daleks)
The larger Daleks of the New Dalek Paradigm, Supreme, Eternal, Strategist, Scientist and Drone, were distinct in that their taller grating sections had no rings, consisting of four black collars. (TV: Victory of the Daleks)
The bronze "Quasimodo Dalek", which was reconstructed by unfamiliar humans, had a grating section which was ordered with the neck grille atop three horizontal neck rings. (COMIC: The Dalek Project)
The dark green, robotic Proto-Daleks, which were constructed by the British and Germans as part of the Dalek Project during the First World War, had distinct grating sections; the British Proto-Daleks had two thin metal bands wrapped around the grating section, while the German Proto-Daleks uniquely had no mesh, instead just solid metal with several lateral grooves. (COMIC: The Dalek Project)