whats the use of memory adresses ?

[E3h7X9L8]

saw this in a code, and i have seen in many other complex algorithms uses of memory adresses , whats the use of them?

  for (n = 0; n <= 5; n++){
	   fprintf(outfile, "%c", headers[n] & 0x000000FF);
	   fprintf(outfile, "%c", (headers[n] & 0x0000FF00) >> 8);
	   fprintf(outfile, "%c", (headers[n] & 0x00FF0000) >> 16);
	   fprintf(outfile, "%c", (headers[n] & (unsigned int) 0xFF000000) >> 24);
	}

[Aceix]

these are bitwise operations. check: stackoverflow.com/questions/4058339/what-is-0xff-and-why-is-it-shifted-24-times

Aceix.