Hi Helen - thank you for the feedback, you make some great points!

I definitely need to iron out who the target market is, but for the time being I have expanded the note to include "(though you are introduced to these topics later – so don't panic if you don't know what they are just yet)."

I think I had envisaged that people coming to this book would have already made their minds up about learning Rails and perhaps already looked at some of the other books but felt a bit out of their depth - so would have probably come across some of the terms. Hence I though that I'd keep the more in-depth explanations to their respective chapters. But yeah I totally see what you mean so I may have to rethink that! Thanks again for the feedback.