question about information column for TCP packets

I am working on a school project where we are analyzing networks using wireshark. We would like to try to figure out how many packets are lost within each conversation. I wrote a small program that accepts a csv generated from wireshark, and parses it into packet objects. I am a little confused about the Information column on TCP packets. We get multiple packets with the same Ack,Win, and Len values, but Seq number is always different. Why is this happening? What does the information column of a TCP packet capture really mean?