FDM Group interview questions

I had applied online for the Software Engineering Graduate programme alongside the Master's in Applied Computer Sciene that they offer. I had to upload a CV and that was it! Very quick process. I was then invited to a video Interview within 1 week, with 4 questions, after the video interview I got an offer to come to the assessment center

-math test 20 min -(behavior interview 7-10 min) and (technical interview 7-10 min) -lunch -aptitude test 50 min -venn diagram test 50 min -tell me about yourself -SQL : what is the diff of primary key and foreign key what is the diff of different joins, what are they -JAVA: what is the diff of object and class what is the diff of while loop and for loop how to describe a loop to a kid, for example studying, playing, sleeping