Hidden conditions are those that are not immediately obvious or visible, but still have an effect on a situation. They can be physical, mental, or emotional and can be difficult to identify. Strings are a series of characters, such as letters, numbers, or symbols, that are connected together to form a single entity. Strings are often used in programming languages to represent data or instructions. In the context of hidden conditions, strings can refer to the underlying connections between different elements that make up a situation.