i noticed (week 4) that the honey is being capped, what exactly is the capped honey for?
When the honey is capped it means the bees feel they have an excess of stores above what they will need in the immediate future. If you are still feeding syrup, you can stop. The bees will use that capped honey later in the year, perhaps during a dearth or in the winter. Capped honey is a good sign that the hive is prosperous.
That and it also means that the honey is ready to be harvested. Bees won't cap the honey until it below 18.5 % water content. Once it is ready they cap it to protect it.
Jim
Capped honey is money in the bank. All you have now is to extract it.