Pine trees of different sizes are bought (some are real and some are plastic) and then covered with Christmas decorations. It is then traditional to put an angel or a star at the top of your Christmas tree, and the presents underneath.
Enter Santa Claus/Father Christmas. He is the big fat man dressed in red and white who brings presents to all the children, by flying on a sleigh pulled by 8 reindeers and coming down the chimney. Each year he has a list of children who've been naughty and nice and all the nice children will get a present on Christmas morning. In some cultures like Germany, naughty children will get a sack of potatoes or a broomstick. Children leave a Christmas stocking hanging on the wall. Santa Claus originated from a man called Saint Nicholas. He was a generous man, famous for giving gifts to the poor. While children were sleeping he would lay the presents down for them - surprising them when they woke up. This is why children today hang stocking up, hoping for St. Nicholas to surprise them with presents.