wat is all this and how do they differ from each other

VHDL,VHSIC hardware descrition Language,ASIC Designing,Verilog,Oracle,Orcad,Pspice Pls pls expalin it will be reallya great favour

VHDL is Very High Speed Integrated Circuit (VHSIC) Hardware Description Language. This is a language standardised by IEEE to describe Digital ICs circuits. This can be written like a computer language and then the described circuit can be simulated or fabricated.
ASIC (Application Specific Integrated Circuit) Designing is the design of a IC for a particular application, say for example a capacitive sensor or maybe a digital IC doing a particular task.
Verilog is another Hardware Description Language but with a different Syntax than VHDL ( more like C)
Oracle is a Database Management System.
Orcad is a software tool to do board level design. It also has PCB designing capabilities.
PSpice is the Spice version that comes with ORCAD to simulate circuits.