Why are relative addresses on Denver with a slash, but not on the server?

Question

PHP

Newbie. Did a project in Denver. Everything works, sat satisfied.
Transferred to the server (debian) - does not work. In all relative addresses, the leading slash had to be removed.
Why?
And on what to develop from a computer so that the transfer is "rrrase and done"?

Answer 1

On an environment as similar as possible to production. Look towards Vagrant