can you please help me and tell me what is ssi and csi and the different between them

 

There are HUNDREDS of possibilities for those two acronyms.

I suggest using google, by searching for "CSI definition" and also "SSI definition". The information by context you have provided is insufficient and since you know better what you need, you will discover the answer to your question much quicker than we could guess what you are wanting.

 

Stage Stores Incorporated (on the New York Stock Exchange) versus Crime Scene Investigation?
got me stumped!