major source of vs main source of

Examples:

• The river is a major source of water for the city.
• The company is a major source of employment in the area.
• Renewable energy is a major source of power in the country.
• The internet has become a major source of information for many people.
• Healthy fats are a major source of energy for the body.

Alternatives:

• primary source of
• key source of
• significant source of
• important source of
• dominant source of

Examples:

• The sun is the main source of light and heat for the Earth.
• Her father was the main source of inspiration for her art.
• The library is the main source of books for the community.
• The factory is the main source of pollution in the area.
• Fresh fruits and vegetables are the main source of vitamins and minerals.

Alternatives:

• primary source of
• key source of
• significant source of
• important source of
• dominant source of