A "1:1 ratio" means that two quantities are equal in size or amount. For example, if you have one apple and one orange, the ratio of apples to oranges is 1:1. This concept is often used in various fields, including mathematics, cooking, and science, to indicate balance or equality between two items. In practical terms, a 1:1 ratio can be applied in recipes, where one cup of flour might be mixed with one cup of sugar. It is also relevant in finance, where a 1:1 ratio of assets to liabilities indicates a balanced financial position, ensuring that what is owned equals what is owed.