A legislator is someone who creates laws. This process can often require dozens or hundreds of individuals, meetings, and debates but, in the end, the result is that a legislator is a person who establishes the laws of a country. In the United States (US), legislators belong to the legislative branch of the US government, and at a federal level serve in Congress in either the House of Representatives or the Senate. In the United Kingdom, members of Parliament serve as the chief legislators of the nation. Members of these bodies work to draft, discuss, and vote on laws that are then passed and established as regulations and statutes for the entire country.
Not every nation divides its legislators from other government officers, and in some cases a legislator of the laws may also be an executor of those laws. The structure of American government was established specifically to avoid this; as such, a convalescence of power can often lead to corruption or at least a reduction of viewpoints and voices within the political process. In the US, federal governmental powers are divided into three different branches: the legislative, the executive, and the judicial. This is often referred to as the separation of powers and is the principal behind much of American government at every level.
In other countries, there is not always such a division of power, and a legislator who creates the laws can also be the person who decides on the legality of those laws and enforces them upon the citizens of the country. While this is not an inherently corrupt system, it may have a tendency for more opportunities for corruption. With power spread out among fewer individuals, it is also likely to be easier for one corrupt person to make a far more tremendous impact.
A legislator in the US who works at the federal level belongs to either the House of Representatives or the Senate. Those in the House, known as representatives, serve for two-year terms and their numbers for each state are based on the population of that state. Senators serve for six years and there are only two senators from each state. For a law to pass in the US, it must receive a certain number of votes in both houses of Congress, laws dictating the numerical majority required to pass. Once it passes in Congress, it can then be signed into law by the president of the United States, who is the head of the executive branch that serves to execute and uphold the laws, and interpreted by the judicial branch that serves to ensure that new laws do not unduly break or nullify previous laws.