A file system provides two resources to the user, blocks for data and inodes for files. Each file consumes one inode. File data is stored in data blocks. Data blocks are usually made up of 1Kbyte blocks.
Assuming no directories exist, a user can exceed his or her inode quota by creating all empty files without using any blocks. A user can also use one inode, yet exceed his or her block quota, by creating one file that is large enough to consume all the data blocks in the user's quota.