A secured network connection( eg SSL ) is handled by the web server correct?

Basically a php programmer does not need to handle the encrypting and decrypting of the messages? The web server handles all the encryption and decryption, and that means by the requested php page from the server is reached, the message is already decrypted?

yes. can't see how any one could answer more fully :-)

Yes, the web server will handle SSL 99%. So you don't have to make any modifications to your code. However, be aware that on a SSL page, the encryption expects all objects on the page to be secure. I.e. loading an external source img will throw off your SSL.