By default, articles are published automatically and immediately when they're saved. You can instead enable article approval for your site, which requires that new articles pass a review process before being published. The article approval process uses roles to control its flow:
To view tasks available to you, click the Control menu, then select My tasks. The position and style of this menu may vary across different site templates, but should resemble the following:
This will take you to a list of tasks that you are able to take action on. An example is below:
You can click View requester details to view basic information about the person who initiated the task. For article approvals, this is the original author. To start processing a task, click the Process button.