Short answers, pulled from the story.
The Parliament of the United Kingdom is the supreme legislative body of the United Kingdom, with authority to legislate for the Crown Dependencies and British Overseas Territories as well. It meets at the Palace of Westminster in London and comprises three elements: the sovereign, the House of Lords, and the House of Commons.
The Parliament of Great Britain was formed in 1707 following the union of the English and Scottish Parliaments. It became the Parliament of the United Kingdom of Great Britain and Ireland on the 1st of January 1801, and was renamed to include "Northern Ireland" by the Royal and Parliamentary Titles Act 1927, five years after the Irish Free State seceded.
The House of Lords can scrutinise and delay most legislation for a maximum of two parliamentary sessions over a year, but cannot block money bills at all. The Parliament Acts of 1911 and 1949 imposed these limits; the Lords retain the unrestricted power only to veto bills that would extend the life of a parliament.
The doors of the Commons are slammed shut against Black Rod to symbolise Parliament's independence from the monarch. The tradition dates to the 3rd of January 1642, when King Charles I entered the Commons to arrest five members, including John Hampden, an action that helped trigger the English Civil War. No British monarch has entered the Commons while it is in session since.
The People's Charter, presented to Parliament in 1838, 1842, and 1848, demanded a vote for every man aged twenty-one and above, the secret ballot, the removal of property qualifications for MPs, payment for members, equally populated constituencies, and annual parliamentary elections. All but the last of these demands were eventually enacted.
The emblem is a crowned portcullis, officially granted by the Queen in 1996. The portcullis was originally the badge of English noble families from the 14th century, later adopted by the Tudor dynasty, and its widespread use throughout the Palace of Westminster dates to the 19th-century rebuilding by Charles Barry and Augustus Pugin after the 1834 fire.