With Unix we talk about “boot” a system, with z/OS we talk about IPL (Initial Program Load). IPL is a hardware function, not a program run on the system. The IPL function reads 24 bytes from an operator-specified or pre-configured device into memory starting at location zero.

With Unix we talk about “files”, with z/OS we talk about Datasets. Datasets are not unstructured streams of bytes, but rather are organized in various logical record and block structures determined by the DSORG (data set organization), RECFM (record format), and other parameters. Programmers utilize various access methods (such as QSAM or VSAM) in programs reading and writing data sets, their choice depending on given data set organization.

With Unix we have the system configuration data in the /etc, with z/OS we have PARMLIB which control how the system IPLs and how address spaces behave.

With Unix we have the Shell scripts, Awk, Perl,.., with z/OS we have REXX execs and CLISTS.

With Unix we have threads which are supported by the Kernel, with z/OS we have tasks or a service request block (SRB).

With Unix we edit data with Vi, emacs, sed, with z/OS we use ISPF, which is more powerful than you can think..

With Unix we have the ps and kill command, to view processes and kill them, with z/OS we have SDSF who allow to view and terminate a job.