I can't answer this question for every country involved in the war, but I can tell you that:

Russians call it Вели́кая Оте́чественная война́ (Velikaya Otechestvennaya voyna) which is generally translated "Great Patriotic War." In this context Оте́чественная (Patriotic, or for the Fatherland) has implications of a defensive war to defend the country, which Patriotic doesn't necessarily imply in English. It's also notable that this refers to the USSR's war with Germany; it doesn't include 1939 when Germany was fighting Britain and France, but the USSR was not at war with Germany.

The Chinese generally talk about 抗日战争, which means something like "anti-Japanese war" or "War of resistance against Japan." This refers to the period 1937-1945, as Japan and China's war started before WW2. For this reason it's sometimes called the 8-year war (or 14 year war). From the Chinese perspective, Japan invaded China, and then later the British and Americans were also attacked by Japan and so allied with China. But of course China never really fought Italy, Germany, etc, so for the Chinese the Nazis are pretty marginal to the war - it's not that the Chinese think the Nazis are irrelevant or other people's wars don't matter per-se, but it's really not the focus of their WW2 historiography, which is all about Japan, for obvious reasons. (It should also be noted how important the anti-Japanese war has been politically to the Chinese Communist Party; the historiography of the war has been heavily affected by the government's political aims of nation-building and ensuring loyalty to the Regime. Focusing on China's victim-hood at the hands of the Japanese militarist invader, who even now are just across the water where they could invade again, has been a key political tool. But the crimes of the Nazis or Italian Fascists serves no particular political purpose.)

So, you can see that every country sees things from their country's perspective: Britain and America fought across multiple continents against multiple enemies.

The timeframes looked at are also different, depending on the view of the country. For Russians, the war is shorter than for the British; for the Chinese it's longer. And one could point out that of course, the Anglo-speaking world does the same. Why do we consider 1939 the start of WW2 when the Japanese had already conquered parts of China? Why do American historians focus far more on the American efforts in Europe or the Pacific than they do on the Blitz, while British historians look far more at the Blitz than the crimes of the Ustasha in the Balkans?

The Japanese also have their own name for the war, but all I know about that is what you can read on wikipedia, so I'd rather let someone else comment on that.