legrega wrote:...what does SVC...stands for
Svc sands for (S
)e which really means a Windows NT Service - by ticking and removing the ticks in an Svc box you install and uninstall a Windows NT Service.
legrega wrote:when must they be checked and why and when NOT?
You only need to tick the Svc boxes next to those components that you wish to start every time you boot your PC - a Windows NT Service.
Usually, in a default XAMPP development environment, you would not normally require the components to be started every time you boot your PC but rather Start and Stop the components manually when you need to work on and/or test your web projects, this way you tend to conserve your system resources etc. for other tasks.
legrega wrote:The first time I start a service (eg Apache)
Best to call it Start a Component
rather than Start a Service which may help to eliminate any confusion as the Svc boxes install the NT Service as described above and the Start and Stop buttons start and stop the relevant XAMPP components
legrega wrote:...it asks me where should I allow it to communicate. Primarily it is checked only home network.
What asks you this question?
Is this a question from your router or firewall perhaps?
Usually it will block attempts to access the server from outside your home network.
legrega wrote:Should I also allow this services to communicate on public networks?
Yes. if you are running your server so it can be accessed from the Internet using your WAN address or No if you only want access to your server from within your home network.
legrega wrote:...And how is this at home different them at library where different
people will use them?
I have no way of knowing how your library is set up for using a web server - ask your library.
legrega wrote:Because I clicked too quick in allowing a service to communicate
through a network (home/public access) where can I change this in
windows 7 and win xp?
Perhaps consult your router configuration and/or your Windows firewall configuration help files.
More XAMPP reading here:\xampp\readme_en.txt