1,000 bytes, strictly doesn't have a name. A kilobyte is 1,024 bytes.
However, hard drive manufactures round this down to 1,000 bytes, so you can argue that 1,000 bytes is called a kilobyte.
Hard Drives that are advertised as 1TB drives often only have 1,000GB, not the 1,024GB they should have by definition... Always read the label!