If you subscribe to the all inclusive definition of the Holocaust whereby every bad thing that happened to people during World War 2 is "the Holocaust," then you are correct.
No I subscribe to the wider, and now universally accepted definition of The Holocaust, as per that given in the Encyclopaedia Brittanoica
"Holocaust, Hebrew Shoʾah, Yiddish and Hebrew Ḥurban (“Destruction”),
The systematic state-sponsored killing of six million Jewish men, women, and children and millions of others by Nazi Germany and its collaborators during World War II.
Included in that definition is
► The wholesale slaughter of Jews, Gypsies, the mentally deficient and the physically handicapped in the death camps.
►The use of Jews, Gypsies, the mentally deficient and the physically handicapped for inhuman medical experimentation.
► The enslavement of Jews, Gypsies and other undesirables as in the manufacture of goods and materiel for the German war effort.
I'm more narrow in my definition.
Then you are about 50 years out of date.
The Jews were the only people singled out for extermination.
Incorrect. Romany people were also singled out for elimination.
The Holocaust was a Jewish tragedy and nobody elses. That doesn't mean that the deaths of millions of innocent people don't matter. It's just that they aren't part of the Holocaust.
The "six million" figure used for Jews killed during the Holocaust includes deaths attributable to beatings, starvation, street executions, lethal experiments, deaths in concentration camps, overwork in forced labour and forced relocations. While the Nazis marked the Jews for complete extermination they were not all just gassed and they were not the only ones gassed. The Nazis used whatever means were available. Further, many non-Jewish victims also died in concentration camps by gassing, lethal experiments, starvation, overwork in forced labour, or beatings, but a greater number died due to the Nazi's aggressive tactics in rounding up their victims for relocation.
The Nazis tried not just to annihilate all Jews, but they targeted all other enemies of the state. Every Jew was to be wiped out, and that millions of non-Jews were also killed goes to show their determination to eliminate anyone who could even remotely be considered an enemy of the state.
Current estimates based on documents from Nazi war records, and official government documents of various countries, place the death toll of people murdered by the Nazis during the Holocaust as conservatively over 15 million non-combatant people, perhaps as many as 26 million.. The exact figures will most likely6 never be n known