EASA Part 66 and Part 147 are regulations established by the European Union Aviation Safety Agency (EASA) related to aircraft maintenance and maintenance training. Here's a brief overview of each:

1. **EASA Part 66**:
   - **Aircraft Maintenance License**: EASA Part 66 sets the standards and requirements for obtaining and holding an Aircraft Maintenance License (AML) in Europe. This license is required for individuals who perform aircraft maintenance tasks, including inspections, repairs, and modifications.

   - **Categories and Subcategories**: Part 66 categorizes aircraft maintenance licenses into various categories (A, B1, B2, etc.) and subcategories (e.g., A1, A3, B1.1, B1.3, etc.), each representing a specific type of aircraft and associated systems.

   - **Experience and Training**: To obtain an AML, individuals must meet specific experience and training requirements, which often include completing an approved Part 147 aircraft maintenance training program.

   - **Continuing Education**: Licensed aircraft maintenance engineers are also required to undergo continuous training and fulfill ongoing educational requirements to keep their licenses current.

2. **EASA Part 147**:
   - **Maintenance Training Organizations**: EASA Part 147 outlines the requirements and standards for Maintenance Training Organizations (MTOs). These organizations are responsible for providing approved training programs to individuals aspiring to become aircraft maintenance engineers.

   - **Training Programs**: Part 147-compliant training programs cover various aircraft categories and subcategories as defined in Part 66. These programs include theoretical and practical training components.

   - **Approval**: MTOs must obtain approval from EASA to provide training programs. They must meet strict criteria, including having qualified instructors, adequate facilities, and the necessary training equipment.

   - **Certification**: Successful completion of an EASA Part 147-approved training program can lead to eligibility for the relevant Part 66 AML examinations.

EASA regulations are designed to ensure the safety and competence of individuals involved in aircraft maintenance within the European Union. Compliance with these regulations is crucial for maintaining the airworthiness of aircraft and promoting aviation safety.

Please note that specific requirements and regulations may change over time, so it's essential to consult the latest versions of EASA Part 66 and Part 147 documents or seek guidance from EASA or relevant aviation authorities for the most up-to-date information.