In Part 1 of IELTS Speaking, the examiner usually chooses the first topic out of these two: Work / Studies or Accommodation
IELTS Speaking Vocabulary: Studies
IELTS Speaking Vocabulary: Accommodation
In either IELTS Writing or Speaking part you may come across essay question or speaking topics like Crime, Prisons, Crime Prevention, Community service, Crimes on TV, etc. If you do not know the specific vocabulary for this topic, it will be difficult to get a decent score for the Lexical Resource criterion - the variety of vocabulary.
IELTS Academic Writing Task 1 Vocabulary - words and phrases for IELTS graphs: Line graphs, Bar charts, Tables, Pie charts.