Linux supports many file system types like Ext2, Ext3, Ext4, NFS, FAT16, FAT32, NTFS etc. To find out what type of file systems are mounted in your system, issue the command
$ df -T
Output from the command
Filesystem Type 1K-blocks Used Available Use% Mounted on
/dev/sda1 ext4 94088076 9090252 80218356 11% /
udev devtmpfs 1023536 4 1023532 1% /dev