Why some people say 1 kilobyte is 1024 bytes and others say it’s 1000 bytes? Where do we use 1 kB = 1000 bytes, 1 MB = 1000 kB, 1 GB = 1000 MB, 1 TB = 1000 GB? And where do we use 1 KB = 1024 bytes, 1 MB = 1024 KB, 1 GB = 1024 MB, 1 TB = 1024 GB?