Apologies for this, I am a student trying to learn C++ and I just thought it'd be better to ask than to not know.

I understand what the "address of" operator `&` and the `const` keyword mean separately. But when I was reading some sample code I saw `const&`, and I just wanted to know what it means.

It was used in place of an argument in a function prototype, for example:

```
void function (type_Name const&);

```

If only one of them were used I would understand but I am a little confused here, so some professional insight would be great.