Brent crude oil drops below $100 amid US-Iran diplomatic talks

Unrefined petroleum extracted from the ground; Brent and WTI are its main global price benchmarks.

Oil prices feed into fuel, transport and goods costs, and so into inflation.

The way geography, resources and power shape relations and rivalries between countries.

Geopolitical tensions influence trade, energy prices and security around the world.

A digital currency secured by cryptography and recorded on a blockchain, without a central bank issuing it.

Crypto prices are volatile, and governments are still deciding how to regulate it.