A ceremony of Introduction takes place in the House of Lords before each Peer is able to take his or her seat in the House. It is a short ceremony lasting about 5 minutes at the beginning of business in the Lords.
An introduction is also the formal start of a Bill's progress through Parliament when the Bill is given its first reading and ordered to be printed.
Related information on this subject can be found from the following links.
Related glossary term: Writ of summons
About Parliament: Passage of a Bill