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?
Why is the iPhone's 1 GB RAM touted to be able to compete with more than 2 GB RAM of Android phones?