Introduction:
Fluids are substances that can flow and take the shape of the container they are placed in. They are a state of matter and can exist as gases and liquids. In this question, we need to determine which of the given options correctly identify fluids. The correct answer is option C, which states that fluids are both gases and liquids.

Explanation:

1. Gases:
Gases are one of the states of matter and can be considered as fluids. They have particles that are in constant motion and are not held together by strong intermolecular forces. Gases can be compressed and they fill the entire volume of the container they are placed in. Examples of gases include oxygen, nitrogen, carbon dioxide, and helium.

2. Liquids:
Liquids are also a state of matter and are considered fluids. Unlike gases, liquids have particles that are closer together and are held together by intermolecular forces. Liquids have a definite volume but do not have a definite shape. They take the shape of the container they are placed in. Examples of liquids include water, milk, oil, and juice.

3. Fluids are Gases and Liquids:
Fluids encompass both gases and liquids. They share the common property of being able to flow and take the shape of their containers. While gases and liquids have differences in their particle arrangement and intermolecular forces, they both exhibit fluidity. The ability to flow is what defines fluids.

Conclusion:
In conclusion, fluids include both gases and liquids. Gases are characterized by particles that are far apart and can be compressed, while liquids have particles that are closer together and have a definite volume. Both gases and liquids exhibit fluidity, which is the ability to flow and take the shape of the container they are placed in.