Credential in the context of "Professional development"

An expert is somebody who has a broad and deep understanding and competence in terms of knowledge, skill and experience through practice and education in a particular field or area of study. Informally, an expert is someone widely recognized as a reliable source of technique or skill whose faculty for judging or deciding rightly, justly, or wisely is accorded authority and status by peers or the public in a specific well-distinguished domain. An expert, more generally, is a person with extensive knowledge or ability based on research, experience, or occupation and in a particular area of study. Experts are called in for advice on their respective subject, but they do not always agree on the particulars of a field of study. An expert can be believed, by virtue of credentials, training, education, profession, publication or experience, to have special knowledge of a subject beyond that of the average person, sufficient that others may officially (and legally) rely upon the individual's opinion on that topic. Historically, an expert was referred to as a sage. The individual was usually a profound thinker distinguished for wisdom and sound judgment.

In specific fields, the definition of expert is well established by consensus and therefore it is not always necessary for individuals to have a professional or academic qualification for them to be accepted as an expert. In this respect, a shepherd with fifty years of experience tending flocks would be widely recognized as having complete expertise in the use and training of sheep dogs and the care of sheep.

Unreported employment, also known as unlawful employment, illegal employment, working under the table or off the books is employment that is illegal and not reported to the government. The employer or the employee often does so for tax evasion or avoiding and violating other laws such as obtaining unemployment benefits while being employed. The working contract is made without social security costs and does typically not provide health insurance, paid parental leave, paid vacation or pension funds. It is a part of what has been called the underground economy, shadow economy, black market or the non-observed economy.

Payments are generally in cash, and the employer often does not check the employee's background or credentials, as is sometimes required by law or otherwise expected by the industry's client base, such as a license or professional certification.

A turnstile (also called a gateline, baffle gate, automated gate, turn gate in some regions) is a form of gate which allows one person to pass at a time. A turnstile can be configured to enforce one-way human traffic. In addition, a turnstile can restrict passage only to people who insert a coin, ticket, transit pass, security credential, or other method of payment or verification. Modern turnstiles can incorporate biometrics, including retina scanning, fingerprints, and other individual human characteristics which can be scanned.

A turnstile can be used in the case of paid access (sometimes called a faregate or ticket barrier when used for this purpose), for example to access public transport, a pay toilet, or to restrict access to authorized people, for example in the lobby of an office building.

A market system (or market ecosystem) is any systematic process enabling many market players to offer and demand: helping buyers and sellers interact and make deals. It is not just the price mechanism but the entire system of regulation, qualification, credentials, reputations and clearing that surrounds that mechanism and makes it operate in a social context. Some authors use the term "market system" to refer to specifically to the free market system. This article focuses on the more general sense of the term according to which there are a variety of different market systems.

Market systems are different from voting systems. A market system relies on buyers and sellers being constantly involved and unequally enabled; in a voting system, candidates seek the support of voters on a less regular basis. In addition (a) buyers make decisions on their own behalves, whereas voters make decisions for collectives, (b) voters are usually fully aware of their participation in social decision-making, whereas buyers are often unaware of the secondary repercussions of their acts, (c) responsibility for making purchasing decisions is concentrated on the individual buyer, whereas responsibility for making collective decisions is divided, (d) different buying decisions at the same time are made under conditions of scarcity --- the selection of one thing precludes the selection of another, whereas different voting decisions are not --- one can vote for a president and a judge in the same election without one vote precluding the other, and (e) under ordinary conditions, a buyer is choosing to buy an actual good and is therefore never overruled in his choice, whereas it is the nature of voting that the voter is choosing among potential alternatives and may be overruled by other voters. However, the interactions between market and voting systems are an important aspect of political economy, and some argue they are hard to differentiate; for example, systems like cumulative voting and runoff voting involve a degree of market-like bargaining and trade-off, rather than simple statements of choice.