what does the “Flipped E” thingy means and what it’s used for ?

i'm a beginner in Japanese and i was reading about particles when i came across this line

ジョンはイギリス人です

what does the flipped E (second character) used for ? i also came across long dash or em-dash and can't understand it's meaning since it wasn't there in any kana. is it kanji or a category of it's own ??