Assume that you open this html in your desktop: https://riino.site/download/pat_test.html

'/' Means root ,this will navigate you to root(Highest Level): https://riino.site/test/

Without '/', this will navigate you to SAME level of current path: https://riino.site/download/test/ , including base url

'./' Means SAME level,too. This will navigate you to root: https://riino.site/download/test/

'../' Means PARENT level, here the parent level is 'Desktop', so relocate in same level as Desktop. This will navigate you to root: https://riino.site/test/

'.../' is not a standard usage, here you mean navigate to text1/text2, while text1 or text2 can be blank, therefore, it will lead you to https://riino.site/download/.../

'test/' is a sample like the one above, which will lead you to https://riino.site/download/test/

Here is a case neither text1 nor text2 is blank, which will lead you to https://riino.site/download/test1/text2

Here is a case neither text1 nor text2 is blank,but we add '/' which will lead you to https://riino.site/test1/text2

With a 'Protocol', this will navigate you to a new URL, starts with this protocal.

Without Protocol, SAME level of current path.

Go deep into www.test.com/homepage/ , we can actually get a 'index.html' because many modern websites can “rewrite” URLs

For example:

https://www.google.com/index.html is totally same as https://www.google.com/