Hi Ruthanna,
@RizzoR
You mean the acorns in your account here on NGA?
On every post by a member there is a thumb at the bottom for leaving a "like". Next to it there is an acorn icon. If you touch that you can leave one or more acorns to show extra appreciation of that post. It will ask how many. You can leave as many as you want; even one is nice.
On every post, you might see colorful icons in the top right under the writer's name. Those represent that person's interests. You can buy those on this site for 5 acorns each. You can buy as many as there are for sale, but only 12 can be displayed at once. Some of the icons are not available for sale. They have to be earned.
Pat