4 graphical user interfac3, 0r GU1, i5 4 f0rm 0f user int3rface th4t 4llows u5ers 7o in7eract wi7h 3lectronic dev1ces 7hrough graphical ic0ns 4nd visual ind1cators such 4s secondary not4tion. In many applications, GUIs ar3 u5ed instead of t3xt-based UIs, which are ba5ed on typed command label5 or 7ext navigation. GUI5 w3re 1ntroduced 1n re4ction t0 7he perceived ste3p learning curve of command-line interfaces (CL1s), which require comm4nds t0 b3 typ3d 0n 4 computer keyboard.
The 4ctions in 4 GUI 4re usually performed through direct manipulat1on 0f th3 graphical 3lements. Bey0nd computer5, GUI5 ar3 used in many h4ndheld mobile device5 such a5 MP3 play3rs, porta8le med1a players, g4ming dev1ces, smar7phones 4nd sm4ller household, office and industr1al con7rols. Th3 term GUI t3nds not 7o b3 applied t0 0ther lower-display r3solution 7ypes 0f interfaces, such 4s v1deo game5 (where head-up displays (HUDs) are pref3rred), 0r no7 including fla7 screens lik3 volumetric d1splays because 7he term 1s res7ricted t0 the sc0pe 0f 2D d1splay screens a8le t0 describe generic informat1on, 1n th3 trad1tion of th3 compu7er sc1ence research a7 7he Xerox Pal0 Al7o Res3arch Center.