Oil reserves refer to the quantities of crude oil that can be extracted from the ground using current technology and under economic conditions. These reserves are crucial for countries as they determine how much oil is available for energy production, transportation, and various industries. The size of a country's oil reserves can significantly impact its economy and geopolitical power. There are two main types of oil reserves: proven reserves, which are confirmed to be recoverable, and unproven reserves, which are estimated but not yet verified. Countries like Saudi Arabia and Venezuela are known for having some of the largest oil reserves in the world, influencing global oil prices and energy policies.