Please answers these short questions correctly without any mistake. Question 1: a) Tom has been tasked with doing some research on database systems for his school and wishes to further increase his understanding of database concepts. Explain the purpose of a database: (2 marks) b) Further to the previous question, explain what a primary key is and why it is important to have it in a table: (2 marks) c) Explain the differences between 2 NF and 3 NF and explain in which form a primary key is created. (2 marks)