The last one is a "flamoeout" addition. Whether or not you take your hop bags from earlier additions out, the flameout addition gets left in - don't use a bag, just throw the hops in the brewpot. Depending on how you cool and whirlpool etc, somewhere between some and most of the hops will get into your fermenter. That's OK. Many of us don't even use hop bags for any of our hop additions, lots of hops gets into our fermenters and the beer tastes great!
The one after 2 weeks is a dryhop, as Djfriesen says. You can add those directly to your primary, rather than racking to secondary if you want. You can bag them or not (I dryhop with a bag, but many don't). Dryhopping is usually for 7 days. Too much longer than that and some varieties of hops develop a grassy, vegetal character.