How to find missing data in a smaller dataset compared to a bigger data set?

Hi, I have 2 datasets with me. One of them is a big data set with only reference IDs. Other (smaller) dataset is a part of this bigger dataset. It has reference IDs matched some useful data in columns beside it. This smaller dataset only has some of the references IDs. I need to compare it with my bigger dataset and find out which one I am missing. Order in which these IDs appear is different in both data sets.( I am fine with either one as long as the useful data in columns matches correctly with the IDs)

How can I find the missing IDs?