What do these @ % + Symbols next to nick names indicate?

In some channels you may notice that some users may have a symbol in front of their nick while other users don't. These symbols indicate their status in the channel.

@ = Channel Operator. Channel Operators (or called Op for short) are trusted users that have been empowered to moderate and control the channel they are on. They have the ability to kick and ban users. They may also change the topic and have access to special commands called mode commands that non-channel operators do not.
% = Channel Half Operator. Channel Half Operators (or called Halfops for short) are trusted users that have the ability to kick and ban users and change some channel modes but cannot kick or ban other ops.
+ = Voiced User. Voiced users have the ability to continue to speak in the channel when the channel is set moderated (+m) This mode is typically used during emergencies or when a channel has a guest speaker and only those running the chat and the guest are being permitted to speak. In some channels voices are given to special users to indicate they're a VIP. While in other channels its given to every user that joins the channel.