It depends on the context. Typically, records vary wildly. A record could be the data content in any data structure or database, or it could be a string of characters between commas in a CSV file. In the context of your previous thread, a record is a line in the temporary file being worked with.
A register is a tiny bit of memory that is used as temporary storage for data. Things move in and out of registers quickly because there are so few of them and they're in high demand.
thanks, i knew that but it didn't help me when i tried to figure out the code
It's just a matter of figuring out what they mean by the terms they use. A register is a temporary holding pen and a record is a more permanent holding pen. You have one register and a potentially unlimited number of records.