An Advocate, Barrister, Lawyer or a Solicitor

We all know the role of the lawyer varies significantly across legal jurisdictions......
Though sometimes, we get confused in determining the historical difference between these similar professions...........
But is it not required to know the exact meaning of Advocate, Barrister, Lawyer, or a Solicitor? 

Understanding more precisely :

An advocate is one who speaks on behalf of another person, especially in a legal context

Thus can be said that represents the knowledge, skill, ability, or standing to speak for them. The broad equivalent in many English law-based jurisdictions is "barrister".

A barrister is a lawyer found in many common law jurisdictions which employ a split profession in relation to legal representation. In split professions, the other type of lawyer is the solicitor. Solicitors have more direct contact with the clients, whereas barristers often only become involved in a case once advocacy before a court is needed by the client. Barristers are also engaged by solicitors to provide specialist advice on points of law. Barristers are rarely, if ever, instructed by clients directly (although this occurs frequently in tax matters). Instead, the client's solicitors will instruct a barrister on behalf of the client when appropriate.

A lawyer, according to Black's law dictionary, is "a person learned in the law; as an attorney, counsel or solicitor; a person taught to practice law.

Working as a lawyer involves the practical application of abstract legal theories and knowledge to solve specific individualized problems, or to advance the interests of those who retain/ hire lawyers to perform legal services.

A solicitor is a term for Lawyer in many Common law jurisdictions that may make a distinction regarding the type of work done; it is also a title used by government attorneys in some government agencies in the United States. In some common law countries the legal profession is split between solicitors who represent and advise clients, and a barrister who is retained by a solicitor to advocate in a legal hearing or to render a legal opinion.

In some Australian states and in Canada the legal profession is "fused”, which means that a lawyer can simultaneously be a solicitor, barrister, and proctor. Where the legal profession is not "fused" in cases where a trial is necessary a client must retain a solicitor, who will advise him or her and then may deliver a brief to a barrister to act on the solicitor's instructions

Outside government agencies the term "solicitor" is merely "one who solicits", not a legal professional

A solicitor is an attorney, which means they can act in the place of their client for legal purposes (as in signing contracts), and may conduct litigation by making applications to the court, writing letters in litigation to the client's opponent and so on. A barrister is not an attorney and is usually forbidden, either by law or professional rules or both, from "conducting" litigation. This means that while the barrister speaks on the client's behalf in court, the barrister may only do so under supervision of the client's solicitor. This difference in function explains many of the practical differences between the two professions.