"Thank you for the meal!"
Breaking it down literally: in full kanji mode it would be 御馳走様でした -->
ご (御) is an honorable prefix, which combined with ちそう (馳走, effort/behavior) means "entertainment" or "feast".
さま (様) is an honorable suffix usually placed behind people's names (like さん), and is here used to address your host.
でした is simply "was".
So, in a way it translates to something like "you have been a great provider".
The browser spanish lessons gave you gramatical "mini lessons" before each exercise to prepare you for the content. Im exclusively learning Japanese through their mobile app but they dont seem to offer those lessons at all yet. Not sure if its a "in the works" thing for the app/language, or they just dont plan on implementing the feature at all.
It would usually be a sentence used to compliment or thank someone for giving you something as a treat or a favour, something like "Thank you for this". Not everything in Japanese should mean the specific thing it apparently translates to in English. I really hoped Duolingo pointed this out a lot.
It's a token phrase that can always be said after any meal, not just to individuals. I'll say it when nobody's even around. Both this and いただきます at the start of a meal are used far more frequently than their English translations. Like, how often do you really say "Let's eat" at the start of a meal? These set phrases in Japanese are sort of like how we say "gesundheit" every time after anyone sneezes, even if we don't know what it means. Much more rigidly used.
Yes, that's the difference in usage, though CLee has a point regarding the translation.
いただく is a humble version of "to receive", so when you say いただきます ("I humbly receive") at the start of a meal, you could also view that as a way of saying "thank you for the meal". ごちそうさま is just as idiomatic and doesn't literally translate to this in English either.
Ok i like the info but the questions doesnt specify whether its talking about the "Thanks for the meal" before eating (itadakimas) or the one after (gochisousamadeshta). I picked itadakimas and it said it was wrong. How would they go about addressing it in the question, come to think about??? Lol