Click-Through Rate

CTR is the ratio of clicks on a specific link to the number of times a page, email, or advertisement is shown. It is commonly used to measure the success of an online advertising campaign for a particular website, as well as the effectiveness of email campaigns. Click-through rates for ad campaigns vary tremendously. The first online display ad, for AT&T, had a 44% click-through rate. With time, the overall rate of user clicks on webpage banner ads has decreased.

Marie Curie

Maria Salomea Skłodowska-Curie; known simply as Marie Curie, was a Polish and naturalised-French physicist and chemist who conducted pioneering research on radioactivity. She was the first woman to win a Nobel Prize, the first person to win a Nobel Prize twice, and the only person to win a Nobel Prize in two scientific fields. Her husband, Pierre Curie, was a co-winner of her first Nobel Prize, making them the first-ever married couple to win the Nobel Prize.

Ultra Low Emission Zone

The Ultra Low Emission Zone (ULEZ) is an area in London, England, where an emissions standard-based charge is applied to non-compliant road vehicles. Plans were announced by London Mayor Boris Johnson in March 2015 for the zone to come into operation in September 2020. Sadiq Khan, the subsequent mayor, introduced the zone early on 8 April 2019. The zone initially covered Central London, the same area as the existing London congestion charge and raised £224 million in 2022.