What are the differences between the EF 50mm f/1.4 use and EF-S 18-55mm IS

[FREDMCFADDEN]

My daughter has asked for my old camera and I have given it to her. It is the Rebel EOS T1i. She wants some new lens's but before I invest I would like to know a few things. The 2 lens's we currently have are the EF-S 18-55 IS and the EF-S 55-250 mm F/4-5.6 IS. What are the differences between the EF 50mm f/1.4 use and EF-S 18-55mm IS? She wants me to buy the EF 50mm f/1.4. 

Thanks in advance.

[ebiggs1]

"... it is obvious some companies pay for positive reviews which certainly gives the reviewer an agenda."

Hallelujah !  Spot on.  Some are even 'quite' obivious.