The context is "Twenty flame jets zip and zag in complicated sequences creating mesmerizing patterns through 30-metre-high aqua displays"
what does the expression "Zip and Zag" mean?
Thanks in advance.
It looks rather strange to me. I would expect either "zig and zag" (or "zigzag") or just "zip".
Remember - if you don't use correct capitalisation, punctuation and spacing, anything you write will be incorrect.