Symbolic parameter means if you write a one catlog procedure in that you have given a
//ddname dd dsn=somename.
if you are calling the catlog procedure each time the data set name is fixed.But you want to change that data set name when ever you want the you can recode that step like this
//dda dd dsn=&s
if you are using that catalog procedure in some ware another job
//step1 exec=Ctalog procedure name s=abc
this value is repalced in above statement.
//ddname dd dsn=abc
The symbolic parameter is used to override parameters on dd statements.They can be used in both cataloged and instram procedures.provided a convenient means of assigning values to commonly used jcl parameters.Are assigned values in the Proc or EXeC statements.
temporary Parameter: I never heard this parameter. I guess it is temporary dataset
This temporary dataset which ur saying (userid.jobname.jobid.Ddsnumber.xxx ) --which one is right would be created and deleted with in the step itself depends on DISP Paremeter.