This is the 125th most frequent French word.
série
"Series"
Here, 'série' means a sequence of related television episodes, commonly referred to as a 'TV series'.
J'ai regardé une série télévisée hier soir.
I watched a TV series last night.
In this instance, 'série' refers to a set of related books that follow a common theme or storyline.
Cette série de livres est très populaire parmi les jeunes.
This book series is very popular among young people.
For this usage, 'série' signifies a sequence or a set of related items (in this case, questions).