You should see a "Condition" field that indicates whether your battery is performing as it should. If it says "Normal," your battery is operating normally, as Apple explains. But it could also say "Replace Soon," which would mean that the battery is holding less charge than when it was new and should be monitored regularly.
If this field says "Replace Now," it means that the battery is holding significantly less charge but is still safe to continue using. The "Service Battery" option indicates your battery isn't operating normally and should be taken to an Apple Store. You can still use it safely when connected to the right power adapter.