Barrister is a lawyer established in many common law jurisdictions; they offer recommendation on legal issues and are on the front line, representing clients in court. The client's solicitor provides the information and instructions to the barrister.
When not appearing in court, they work in chambers to prepare their court cases and arguments. Barristers are also engaged by solicitors to provide specialist suggestion on points of law. Barristers are rarely, instructed by clients directly. Instead, the client's solicitors will inform a barrister on behalf of the client when convenient.
Historically, the difference was absolute, but in the modern legal age, some countries which had a split legal profession are now characterised by having a combined profession; all persons entitled to practice as a barrister are also entitled to exercise as a solicitor, and vice versa. In practice, the difference may be non-existent, minor, or marked, depending on the jurisdiction.
And in others, Scotland and Ireland for example, there is little overlap. In the United States do not observe a difference between barristers and solicitors. Lawyers are allowed to manage all aspects of litigation and appear before those courts where they have been accepted to the bar.