Wehrmacht (literally “defense force”) was the name of the unified armed forces of Germany from 1935 to 1945. It consisted of the Wehrmacht Heer (army), the Kriegsmarine (navy) and the Luftwaffe (air force). The Waffen-SS, an initially small paramilitary section of Heinrich Himmler’s Allgemeine SS that grew to nearly a million strong during World War II, was not officially part of the Wehrmacht, but subject to OKW, OKH, as well as Field Command. Thus, the Waffen-SS was, de facto, a fourth branch of the Wehrmacht.
The Waffen-SS (German for “Armed SS”, literally “Weapons SS”) was the combat arm of the Schutzstaffel (“Protective Squadron”) or SS. In contrast to the Wehrmacht, Germany’s regular army, the Waffen-SS was an combat unit composed of volunteer troops with particularly strong personal commitments to Nazi ideology and initially selected on racial basis. As stated by Himmler, the primarily goal of SS formations was to fight Jewish people, people considered subhuman by the racist Nazi ideology(i.e Poles, Jews, Roma people) and communists
The Allgemeine SS (General SS) was established in the autumn of 1934 to distinguish certain SS members from the Waffen-SS (Armed SS) and SS-Totenkopfverbände (Death’s Head formations).
further readings

has Mr Adolf Hitler got anything to do with it?
here try this source!

The Schutzstaffel (help·info) (German for “Protective Squadron”), abbreviated SS- or (Runic)- was a major Nazi military organization under Adolf Hitler and the Nazi Party. The SS grew from a small paramilitary unit to an elite force that served as the Führer’s “Praetorian Guard,” the Nazi Party’s “Shield Squadron” and a force with as much political influence as the regular German armed forces. Built upon the Nazi racist ideology, the SS, under Heinrich Himmler’s command, was primarily responsible[citation needed] for the crimes against humanity perpetrated by the Nazis during the Second World War.

Initially smaller than the Ernst Röhm’s Sturmabteilung (Storm Troopers abbreviated SA), the SS grew in size and power due to its exclusive loyalty to Hitler, as opposed to the SA, which was seen as semi-independent and a threat to Hitler’s hegemony over the party. Under Himmler, the SS selected members according to the “Aryan” racist ideology. Developing elite police and military units such as the Waffen SS, Himmler also used the SS to develop an order of men claimed to be superior in racial purity and abilities than other Germans and national groups, the model for the Nazi vision of a “master race.” During the World War, SS units operated alongside the Army and in the final stages of the war, exercised dominance over the Army to eliminate perceived threats to Hitler’s power while implementing his strategies despite the increasingly failing war effort.

The SS was responsible for the vast majority of war crimes perpetrated under the Nazi regime, including the Holocaust. As part of its race-centric functions, the SS oversaw the isolation and displacement of Jewish people from the populations of Germany and conquered territories, seizing their assets and imprisoning them in concentration camps and ghettos where they would be used as slave labor, pending extermination. Chosen to implement the Nazi “Final Solution” for Jews and other groups deemed “inferior,” the SS carried out the enslavement, torture and killing of approximately twelve million people. Most victims were Jews and/or Slavs, but a significant number of victims included homosexuals, Catholics, Gypsies, Jehovah’s Witnesses, journalists, Communists and German civilians who were seen as threats to the regime. Foreseeing Nazi defeat in the war, a significant number of SS personnel organized their escape to South American nations. Many others were captured and prosecuted by Allied authorities at the Nuremberg Trials for war crimes, and absconding SS criminals were the targets of police forces in various Allied nations, post-war Germany, Austria and Israel.

The second is the SS. Not sure about the first.

The SA (Sturmabteilung) and the SS (Schutzstaffel).

The SA were replaced by the SS. In fact, the SS killed a number of the members of the SA in the “Night of the Long Knives.”

The SS were the completely loyal Nazi soldiers. They did the things that the regular military couldn’t be trusted to do.

It was the SS that carried out the Holocaust and is the “later military arm” you’re referring to. If you google SS you’ll find the German that the SS is short for.
As for the other, you might google BLACK SHIRTS or possibly BROWN SHIRTS.
During the war, the Wehrmacht was the German army and the Luftwaffe the German airforce.