Matching Concept:
The matching concept is a fundamental principle in accounting that states that expenses should be recognized and recorded in the same accounting period as the revenues they generate. This concept ensures that financial statements accurately reflect the results of an entity's operations for a specific period. By matching revenues and expenses, the concept allows for the determination of net income or loss.

Matching Assumption:
The matching assumption is an underlying principle of the matching concept. It assumes that the cost of resources consumed to generate revenues should be recognized in the same period as the revenues themselves. This assumption helps ensure that financial statements provide a true and fair view of an entity's financial performance.

Matching Principle:
The matching principle is a specific application of the matching concept. It guides accountants in determining when and how to recognize expenses in relation to revenues. According to this principle, expenses should be recognized in the same accounting period as the revenues they helped generate. This enables a more accurate measurement of an entity's profitability.

Key Differences:

1. Concept vs. Assumption:
- The matching concept is a broader principle that governs the recognition of expenses and revenues in accounting.
- The matching assumption is an underlying assumption that supports the matching concept by assuming that costs should be recognized in the same period as the associated revenues.

2. Scope:
- The matching concept applies to the overall recognition of expenses and revenues in accounting.
- The matching assumption is specifically concerned with the recognition of costs in relation to revenues.

3. Application:
- The matching concept guides the preparation of financial statements by ensuring that expenses are matched with the revenues they generate.
- The matching assumption supports the matching concept by assuming that costs incurred to generate revenues should be recognized in the same period as the revenues themselves.

4. Purpose:
- The purpose of the matching concept is to provide a more accurate representation of an entity's financial performance by aligning expenses with the revenues they help generate.
- The purpose of the matching assumption is to ensure that the recognition of costs and revenues in financial statements adheres to the matching concept.

Conclusion:
In conclusion, the matching concept is a fundamental principle in accounting that guides the recognition of expenses and revenues. The matching assumption supports this concept by assuming that costs should be recognized in the same period as the associated revenues. Together, these principles help ensure that financial statements accurately reflect an entity's financial performance and provide users with reliable information for decision-making.