You would use LiveCycle Designer to create the template for the form and LiveCycle Server ( or probably now Adobe Experience Manager would be used for both parts) but I wanted to answer your question directly.
Assuming the form is created to be accessible, then that is what you will get, the server does not magically make your form accessible, there are some guidelines here, but you need to make sure you follow the guidelines you need for how accessible you want to make the form, and by that I mean, if it is for the UK Government, US Government, EU, etc.... they have there own rules for what is considered accessible.
