Like the Voice is accurate-ish. I don't know how to describe it, but Eurovision is a competition amongst European nations, as well as some outside of Europe like Australia, and Israel (competition has to do with TV rights, but that's another topic). Each country has their own internal competition to choose their representative, then their rep goes to the hosting city for the final competition. Each "band/singer" performs and then they combine a fan vote and the country rep votes to determine the winner. The country rep votes are highly politcal, so it's interesting/funny to see where countries award their points/votes.
The bands/artists aren't just judged on their musical abilities, as many performances that win are based on the entertainment value rather than actual musical/singing abilities, which in my opinion is what makes Eurovision interesting and fun to watch.