What is considered low/medium/high competition?

I have done some searches online and can't find the answer that i'm looking for. As the title says, what is generally considered a low/medium/high competition niche?

If the top 5 competitors have 2000 backlinks from 1000 referring domains roughly and they are of average/low quality. What difficulty would you put something like this in, I would guess medium? This niche has 100,000+ searches per month which could be easily monetised. I'm thinking possibly a goldmine with a few strong web 2.0s, pbn links, etc.

All answers appreciated, Thanks

As per your stats, i think those sites are not much authority. Yes, it might be medium competitive.