renting an apartment in germany

So, I'm not at all clear on what the longest word in the world actually means! Mieten is to rent, but that's all I can figure out. That is a little like what it was like to actually rent an apartment here... even though our landlords speak english, and I know a little german, there are a lot of special german words and special english words that defy translation. So we all just did a lot of smiling and nodding and laughing at each other and ourselves and then we signed some papers. Really that's all I know.