So, I'm making a navigation bar for my website, but I've hit a snag- if I ever want to change the navigation bar, do I have to go ever every single page in my website and change each individual part? I have quite a few pages, so it'll get tedious quickly and take forever. So, is there any way I could use the same HTML text that defines the navigation bar in some other way besides copying, pasting, and re-uploading all the web-pages to my host? I've heard that you can use external files to achieve this, with some code that inserts the text in a file on that part, but I haven't found any tags that can do this.