"Grid tied" / "on-grid" is normal for 99.9% of homes in NZ. It means a power company connection to your home.
The opposite is "off-grid", which means no electrical company connects to your home.
Grid-tied solar: using large solar panels to reduce your home's electricity bill.
Why Grid Tied Solar SUCKS For Emergencies
In emergencies when you lose power from your electrity company. This short video explains why having solar panels on your home won't work, unless you have a fairly complex (and expensive) set up.