Single instruction, multiple data
You can write scalar code and compiler can auto vectorize it to SIMD code or we can ues openmp library to use it. It is like magic in this form or the earlier form.
The Intel Intrinsics Guide is an interactive reference tool for Intel intrinsic instructions, which are C style functions that provide access to many Intel instructions - including Intel® SSE, AVX, AVX-512, and more - without the need to write assembly code. eve is a good SIMD library.
memory is allocated in pages. Intel x86 register is 32 char. Intel x86 page is 4 kB. in C++, int* has to be aligned to alignof(int), you can't use just any address.