People scan the Internet looking for information that helps them understand something, solve a problem or engage in an activity. Stale websites don't have many visitors because there isn't dynamic content that draws people to the table. Writing and posting new content keeps people coming back over and over in a way that encourages them to be engaged.
What does updating content mean?
It means putting interesting things on your site that draw people's attention. It could be posts, sayings, videos, just about anything that attracts people to come back over and over.
Why is it important?
People will come back if they like the content. This can lead to greater sales and influence through repeat visits.
How does it help Search Rankings?
Search rankings improve with fresh content. Search engines will spider and place strong content above information.
How does it draw people to products or ideas?
People who are interested in a particular topic will be attracted to the site by the search terms they use. This in turn should be related to the mission and products/services of the business.