hi i am trying find out what memory
that can hold electric signal code
but don't know what the memory is called

sdram sram

 

That depends on the definition of "electric signal code". The search term "types of computer memory" brings up 79,000,000 hits. Perhaps this article will help - http://www.associatedcontent.com/article/1876173/understanding_7_basic_types_of_computer.html

What does this have to do with the 256 MB to 124 GB memory project?

 

Are you referring to storage for logging of data Such as This Unit?

This is usually done with flash memory, such as is used in flash memory on USB "Thumb Drives". These can be interfaced to a PIC fairly easily at capacities up to 2GB.

Going beyond 2GB (SDHC) requires a bit more in terms of hardware and software.