XML / Apache questions

[Vu Pham]

Sorry for this stupid question. Never worked on this before.

There is a requirement to input data via XML/Apache. I am reading some XML
stuff, and at the same time I have some questions to make thing clearer. 

1. Will I send data to a remote web server via a XML file ?
2. From the client side ( where data will be sent from ), will that action
be able to do via a command line ?
3. If so, what tool helps me to do that ( the client side - my side - is
Linux ) ?
4. My server may also needs to receive data. Then what tool will go with
Apache ( I have Apache on my server ) to receive/parse these XML and write
it to a raw text file ?


Thanks,

Vu