If using corn sugar add 5 cups to your malt extract mix in pot. If using a bucket of unhopped bulk malt extract use only the malt in the bucket and nothing else. No other sugar is needed since the malt contains all of the fermentable sugar that you will need. You will nedd corn sugar for bottling. Place the pot back on the heat and bring it to a boil.
Wort is a term for the unfermented beer.
If you are using a hopped malt extract can and you are not adding bittering hops, then you boil for 15 minutes. You may add finishing hops to this mixture in the last minute. Additional finishing hops should be added at last minute of boil to impart aroma and flavor. Cool your wort with cold water in the fermentor. It is a good idea to chill 3-4 gallons of water overnight.