Can anyone tell me the difference between CREO and SOLIDWORKS Softwares nd inportances ?

The biggest difference between Creo and SolidWorks would be their complexity for users. SolidWorks is a much less complex option and has a quicker learning curve for beginners. Creo is a much more complex program and is aimed at the higher-end CAD market. On the other hand SolidWorks does not have the capabilities to work with large assemblies or design high quality surfaces.

yes , comparitive to others , CATIA is capable to work with large assemblies

Creo is parametric modeling, where we can control the geometry with mathematical equations and much simple to create different multiple features within the same part (family table), and yes it's good in handling huge assemblies. Creo is best in Mechanical design, and Catia is good in surface modeling. Solidworks in the tooling domain (Injection Mold design).

I use both for space flight hardware. If you want to get a job done quickly and efficiently and not require 10,000 clicks of a mouse, use Solidworks. Contrary to what the PROE fans out there say, I will run literal circles around them on a schedule basis using Solidworks. Solidworks is about 400% faster to design the same parts. I've done this engineering study myself, as the bean counters in my company wanted to know why i allocated so many hours to a Creo required job vs a Solidworks job. Simple answer....Its way faster to design in. It supports width mates, where Creo requires you to get out a calculator, Solidworks supports Tables from excel like your already used to, Creo makes you litterally build them from boxes and then break out your programming skills to create the data that should be in that box. Personally I think Creo is old technology stacked on top of old technology. Its very clunky and unpredictable. I can 3 mouse clicks in SW what would take 15 in Creo, and that's almost every command. My customer quotes are severely inflated if Creo is the requirement for the deliverable. Can Creo do what Solidworks does and vise versa, yes! the end result is the same...a 3D model, drawing and Bill of material, and simulation results.