Registers: r: 64 bits e(xtended): 32 - (none): 16
Ax would stand for accumulator
Cx for counter/loops
majority now of free use, except a few like rsp (stack pointer) and rbp (base pointer)
PIE: Position Independent Executables, implemented by default by gcc to leverage Address Space Layout Randomization (ASLR) as a form of mitigation of memory vulnerabilities. Changes resources' address locations.