But it was a totally different installation and I got confused.
If you compile from source from the official latest release, there can be some or significant changes in the software as I understand it.
Here is some info on software being delayed in getting to the repositories.
One thing new Linux users often notice with package managers and repositories is a delay before new software versions reach their systems. For example, when a new version of Mozilla Firefox is released, Windows and Mac users will acquire it from Mozilla. On Linux, your Linux distribution must package the new version and push it out as an update. If you open Firefox’s preferences window on Linux, you’ll note that Firefox has no ability to automatically update itself (assuming you’re using the version of Firefox from your Linux distribution’s repositories).
I want to know what is the difference between two installations?
You could read up on these and go from there:
Overview of new features in Apache HTTP Server 2.4
Overview of new features in Apache HTTP Server 2.2
Here are Apache's features on Wikipedia.
Apache supports a variety of features, many implemented as compiled
modules which extend the core functionality. These can range from
server-side programming language support to authentication schemes.
Some common language interfaces support Perl, Python, Tcl, and PHP.
Popular authentication modules include mod_access, mod_auth,
mod_digest, and mod_auth_digest, the successor to mod_digest. A sample
of other features include Secure Sockets Layer and Transport Layer
Security support (mod_ssl), a proxy module (mod_proxy), a URL rewriter
(mod_rewrite), custom log files (mod_log_config), and filtering
support (mod_include and mod_ext_filter).
Popular compression methods on Apache include the external extension
module, mod_gzip, implemented to help with reduction of the size
(weight) of Web pages served over HTTP. ModSecurity is an open source
intrusion detection and prevention engine for Web applications. Apache
logs can be analyzed through a Web browser using free scripts, such as
AWStats/W3Perl or Visitors.
Virtual hosting allows one Apache installation to serve many different
Web sites. For example, one machine with one Apache installation could
simultaneously serve www.example.com, www.example.org,
Apache features configurable error messages, DBMS-based authentication
databases, and content negotiation. It is also supported by several
graphical user interfaces (GUIs).
It supports password authentication and digital certificate
authentication. Because the source code is freely available, anyone
can adapt the server for specific needs, and there is a large public
library of Apache add-ons.
Here someone is like you trying to understand the difference between the version his Linux distribution uses and newer ones released by the official developer.
Since you don't mention your distribution, I'm assuming that it's Ubuntu, I use Debian Wheezy, and here is apache2 for that release:
root # apt-cache policy apache2
500 http://the.earth.li/debian/ wheezy/main amd64 Packages
500 http://security.debian.org/ wheezy/updates/main amd64 Packages
You can find an explanation and information about the LAMP stack here.
LAMP is an acronym for an archetypal model of web service solution stacks, originally consisting of largely interchangeable components: Linux, the Apache HTTP Server, the MySQL relational database management system, and the PHP programming language. As a solution stack, LAMP is suitable for building dynamic web sites and web applications.1
The LAMP model has since been adapted to other componentry, though typically consisting of free and open-source software. As an example, the equivalent installation on a Microsoft Windows operating system is known as WAMP.