Someone experienced has first-hand knowledge of something. A 10-year veteran is an experienced baseball player.
Experience is time you spend doing or learning something. If you've had a job as a welder, you have welding experience. When someone is described as experienced, it means they have first-hand knowledge about something. An experienced teacher has been teaching for years. An experienced writer has written many books or articles. An experienced soldier has been in the field for a while. People who are experienced tend to be wise: they know what they're talking about.