Summarize this article in one sentence.
The most professional move to make is to hand your 2 weeks notice to your boss first and in person.  You will usually need to schedule a meeting, but if you work at a small company and are on close terms with your boss, you might be able to drop by his or her office unannounced. Close the door behind you as you enter to keep the conversation private. Hand your boss your 2 weeks notice and explain, as you hand it over, what the letter is. Your boss will likely want to discuss the situation with you. Even if your letter already answers the questions posed to you, answer each question completely. Thank your boss as you leave the office and shake hands. This can vary by company, but usually, the Human Resources department will need a copy as well as any other supervisors you work under. If you do send the letter to multiple people, include a “CC” line indicating who has received a copy. This can help facilitate communication and coordination as your company deals with your resignation. Co-workers, mentors, team members, and clients should be told in person about your resignation. They do not need an official copy of your 2 weeks notice. If you offered to finish up any major projects before leaving when you wrote your letter, you need to follow through and finish those projects.  Even if you did not make any promises, you cannot slack off during your final 2 weeks of employment. The transition will be difficult for everyone, and it is your professional duty to make that transition as smooth as possible for the employer you are leaving. Don’t let your company take advantage of you by asking you to do work well beyond the scope of your normal duties in your remaining 2 weeks. Stay polite and professional, but be firm about which tasks you will be completing before you leave.

Summary:
Take your 2 weeks notice directly to your boss. Submit copies to anyone else who may need one. Work hard and tie up loose ends.