The term “solicitor” has several different meanings, depending on the context and where in the world one is. In some parts of the world, a solicitor is a member of the legal profession, with job roles which may vary, depending on regional laws. In other areas, people use the term to refer to someone who solicits services, donations, and other things from people and organizations. This explains the “no solicitors” signs sometimes posted on doors and gates: people aren't trying to keep out lawyers, they are warning advertisers that their presence is unwelcome.
In the legal sense, a solicitor is someone who has undergone legal training and been admitted to the practice of law. In some countries, the legal profession is split into two separate categories: solicitors and barristers. Solicitors handle legal matters outside of court, providing legal advice to clients, preparing legal arguments, and so forth. They are also sometimes admitted to practice in the lower courts. Barristers, on the other hand, actively participate in court, arguing cases before a judge.
In countries where there is a clear division of labor, solicitors are allowed to solicit clients directly, but barristers are not. This means that a solicitor works with a barrister, referring cases to the barrister if it becomes apparent that the case is going to court. People who retain legal counsel usually retain a solicitor, relying on the solicitor's judgment if a barrister is required.
Some regions of the world decided that the divided system did not work, and they streamlined the two professions into one, which explains why people may refer to a legal professional as a “solicitor and barrister.” In other areas, the divided legal system never existed, and legal professionals known as attorneys or lawyers may practice in court as well as out of court.
Countries with a unified legal system in which people can work both in and out of court may reserve the term “solicitor” for the chief legal officer of a regional government. For example, the United States has a Solicitor General who argues on behalf of the Government in the Supreme Court. Other local and regional governments may also retain a chief legal officer who is referred to as the solicitor. A regional solicitor may also be called a state's or town's attorney, a prosecutor, or a district attorney.
As a general rule, the type of solicitor under discussion is usually obvious from the context. People living in nations with unfamiliar legal systems, however, may want to be careful about how they use the term, to ensure that their meaning is understood.