In one sentence, describe what the following article is about:

In the workplace, there will be many occasions for congratulating your colleagues on their new promotion or job. Remember to keep your company culture in mind when you choose how to congratulate someone at work. Don't be overly effusive in a formal office atmosphere - keep it professional. Here are some great ways to congratulate someone at work:  Say "congratulations" in person, with a genuine smile. Write a brief and professional congratulatory note. If you're close to the person, you could take him or her out for drinks or bring a treat to the office for everyone to share. When you're congratulating someone who just got engaged or married, show some excitement for them! Give them a call or write a note on Facebook to tell them you wish them many years of happiness. If you're close, an additional gesture is probably in order:  Send a card with a personal note congratulating the couple. Consider sending a small gift, like flowers or a bottle of wine. If the person is a colleague, have everyone in the office sign a card for the happy coworker. Consider throwing a shower if you're close to the person. A baby on the way is another sentimental occasion that should be marked with a genuine smile and hug. If your friend, relative or colleague announced a pregnancy, say congratulations in person and consider doing the following:  Send a card. It's customary to do so, and you'll find many options in the stationary store. Send a gift. If you feel like it, you could send a little baby gift in anticipation of the birth. Throw a shower. If you're close to the person, you might be the right one to  organize a baby shower. If you notice that someone has overcome some personal hurdles, you might want to show your encouragement and love by congratulating them. For example, maybe your friend just finished a round of chemo and found out that her cancer is in remission, or your aunt just finished getting her degree after many years of hard work. Figure out the gesture that best matches the situation.  Sending a thoughtfully-written note is always a nice idea - especially when the person isn't expecting to get it. Taking the person out to dinner or out for drinks is a good way to celebrate a personal achievement.

Summary:
Congratulate someone on a professional achievement. Share your excitement that someone is getting married. Offer congrats to someone having a baby. Congratulate someone for getting through a tough time.