Mac OS X El Capitan and Mac OS X Sierra both come with Apache pre-installed.
However, since both El Capitan and Sierra run Apache 2.4, you can simply backup the configuration file from Sierra and overwrite it with your El Capitan version. As such, you should take the time to update Sierra’s Apache configuration.everything should be "drag and drop" as far as replacing the new default config files with your old ones -- you may still want to keep the default files as backups though).Furthermore, you should be able to drop custom files (SSL certificates, modules, etc.) into the same locations and have them work as well.So you shouldn't necessarily be concerned that you don't have the latest.When making upgrades to a major piece of software like Apache, you risk making your system unstable.First, create a backup and compare the two configuration files for differences. If you added any extensions to PHP you will need to recompile them.