Apache Server Interview Questions

[Nimy]

How to check the version of Apache server ?
What is meaning of "Listen" in httpd.conf file ?
What is location of log files for Apache server ?
What is Document Root ?
On which port Apache server works?
What is the main difference between <Location> and <Directory> sections?
What do you mean by a valid ServerName directive?
What is the difference between a restart and a graceful restart of a web server?
Which tool can be used for Apache benchmarking?
Can we have two apache servers having diff versions?