Each bit of information you enter on the site is called a node.
Nodes can be pages, images, polls, forum topics, replies, or stories. These are the node types set up on the site. Comments are also nodes.
They all have a timestamp - that is the date and time they are entered. By default they all go in chronological order.
What is sticky used for?
Anything that is always at the top of a page is sticky.
If you want something to stay at the top of a list, even if it’s older, then you make it sticky, then it will always stay at the top. If you make more than one thing sticky in a category, then they will both be at the top with the newest one higher up.
When you don’t need that bit of information any more (e.g. the Christmas play is now in the past and people don’t need to know that it’s coming up) you can edit it and make it not sticky (or delete it altogether).