While using the command line is more efficient and filled with geeky goodness, you can use the GUI for just about everything- it's just a layer on top of the command line. If the majority of what you do is WWW, you may never need to use the command line.
However, sometimes it's fun just to amaze your windows using friends.
This will resize images in the command line. First line gets imagemagick: (note: I'm using Ubuntu, but the command should be the same)
sudo apt-get install imagemagick
mogrify -resize 320x240 Image.png
mogrify -resize 50% Image.png
Works for .jpg as well.
You can even resize an entire folder of pics with this command- a lot faster than any graphical program.
The first line- sudo- is commonly referred to as 'do as superuser', even though the su part of the command really means 'switch user'. Using sudo means you do not have to log in as root to do jobs that require root access. You should avoid logging in as root, and NEVER go online as root. Root access goes even deeper than admin in windows- you can access the kernel as root, and bad things can happen with that much power.
There's much more, things like hdparm that can be used to really customize how linux controls the hard drive.... for the uber geeky only, LOL.
hdparm - get/set hard disk parameters - version v9.43, by Mark Lord.
Usage: hdparm [options] [device ...]
Options:
-a Get/set fs readahead
-A Get/set the drive look-ahead flag (0/1)
-b Get/set bus state (0 == off, 1 == on, 2 == tristate)
-B Set Advanced Power Management setting (1-255)
-c Get/set IDE 32-bit IO setting
-C Check drive power mode status
-d Get/set using_dma flag
-D Enable/disable drive defect management
-E Set cd/dvd drive speed
-f Flush buffer cache for device on exit
-F Flush drive write cache
-g Display drive geometry
-h Display terse usage information
-H Read temperature from drive (Hitachi only)
-i Display drive identification
-I Detailed/current information directly from drive
-J Get/set Western DIgital "Idle3" timeout for a WDC "Green" drive (DANGEROUS)
-k Get/set keep_settings_over_reset flag (0/1)
-K Set drive keep_features_over_reset flag (0/1)
-L Set drive doorlock (0/1) (removable harddisks only)
-m Get/set multiple sector count
-M Get/set acoustic management (0-254, 128: quiet, 254: fast)
-n Get/set ignore-write-errors flag (0/1)
-N Get/set max visible number of sectors (HPA) (VERY DANGEROUS)
-p Set PIO mode on IDE interface chipset (0,1,2,3,4,...)
-P Set drive prefetch count
-q Change next setting quietly
-Q Get/set DMA queue_depth (if supported)
-r Get/set device readonly flag (DANGEROUS to set)
-R Get/set device write-read-verify flag
-s Set power-up in standby flag (0/1) (DANGEROUS)
-S Set standby (spindown) timeout
-t Perform device read timings
-T Perform cache read timings
-u Get/set unmaskirq flag (0/1)
-U Obsolete
-v Use defaults; same as -acdgkmur for IDE drives
-V Display program version and exit immediately
-w Perform device reset (DANGEROUS)
-W Get/set drive write-caching flag (0/1)
-x Obsolete
-X Set IDE xfer mode (DANGEROUS)
-y Put drive in standby mode
-Y Put drive to sleep
-z Re-read partition table
-Z Disable Seagate auto-powersaving mode
--dco-freeze Freeze/lock current device configuration until next power cycle
--dco-identify Read/dump device configuration identify data
--dco-restore Reset device configuration back to factory defaults
--direct Use O_DIRECT to bypass page cache for timings
--drq-hsm-error Crash system with a "stuck DRQ" error (VERY DANGEROUS)
--fallocate Create a file without writing data to disk
--fibmap Show device extents (and fragmentation) for a file
--fwdownload Download firmware file to drive (EXTREMELY DANGEROUS)
--fwdownload-mode3 Download firmware using min-size segments (EXTREMELY DANGEROUS)
--fwdownload-mode3-max Download firmware using max-size segments (EXTREMELY DANGEROUS)
--fwdownload-mode7 Download firmware using a single segment (EXTREMELY DANGEROUS)
--idle-immediate Idle drive immediately
--idle-unload Idle immediately and unload heads
--Istdin Read identify data from stdin as ASCII hex
--Istdout Write identify data to stdout as ASCII hex
--make-bad-sector Deliberately corrupt a sector directly on the media (VERY DANGEROUS)
--offset use with -t, to begin timings at given offset (in GiB) from start of drive
--prefer-ata12 Use 12-byte (instead of 16-byte) SAT commands when possible
--read-sector Read and dump (in hex) a sector directly from the media
--security-help Display help for ATA security commands
--trim-sector-ranges Tell SSD firmware to discard unneeded data sectors: lba:count ..
--trim-sector-ranges-stdin Same as above, but reads lba:count pairs from stdin
--verbose Display extra diagnostics from some commands
--write-sector Repair/overwrite a (possibly bad) sector directly on the media (VERY DANGEROUS)
