Syntax Question

Thanks for reading my post, noob here and just looking at some example code and I tried to search for this but I guess I don't know what I'm searching for?

I see the following segment but when I search all the pages of the code I don't see
call_t anywhere in any of the pages of code but I do see c_call used in multiple places on different pages.

This code appears before setup()

call_t c_call[8] = {0.0};

so my question as dumb as it may be is
what does call_t; do and then was does call_t do for c_call[8]?

I think I understand the c_call[8] = {0.0} which declares and assigns an array of 8 elements, each assigned 0.0...hopefully have that part

That first line doesn't make any sense at all.

A little context would help to figure out the second line. Where have you seen it? Can you post one of those examples or sketches? Or at least a link to it?

Here they are creating a textual menu, when connected with terminal program via com port, but it’s also used to read/write some channel data to the EEPROM.

          Serial.println(F(""));//rev 1.72
          Serial.println(F("I Values (uA x 10):"));//rev 1.72
          //Read I values for UI
          for (idx = 0; idx < 8; idx++){
              switch (type){
                  case 0:
                       temp = String("\tCH" + String(idx+1) + ": " + String(c_call[idx].Ipulse));
                  case 1:
                       temp = String("\tCH" + String(idx+1) + ": " + String(c_call[idx].Iback));
                 // case 2:
                 //      temp = String("\tCH" + String(idx+1) + ": " + String(c_call[idx].Ifast));
                 //      break;

I meant the whole program. That call_t is some custom type being defined in some library that's included in that sketch. What it means depends on how it is defined. How it is defined might be different for different libraries. If you show all of it, I can probably ferret out what it has been defined to do.