why RAM and not the harddisk

[patel_ec]

hello

i have a basic question.

tell me why we are using a RAM in computers.

i mean why processor cant directly deal with harddisk?

if we want processor to deal with harddisk, what r the problems and how solution tends to use RAM?

 

[atmelAVR91]

Access time of RAM is very very low as compared to HARDDISK Media
and again RAM is mapped in processor address space to exec. program from RAM