It might be a humble paper booklet but travellers who possess a British passport enjoy visa-free access to 173 countries. At the other end of the scale, residents of Afghanistan can access just 28 countries with their passports while Iraqi passport
holders can enter only 31.
The map shows how many countries passport holders from different countries can gain access to without needing a visa, or only requiring a visa upon arrival.
Here's a static image of the same map for mobile users who don't like zooming in.