**Explanation:**

When a product carries the logos of ISI, Agmark, or Hallmark, it certifies the quality standards of the product. Let's understand what each of these certifications signifies and how they ensure the quality of the product.

**1. ISI Certification:**

- ISI stands for Indian Standards Institute, which is now known as the Bureau of Indian Standards (BIS).
- ISI certification ensures that the product meets the quality standards and safety requirements set by the BIS.
- It covers a wide range of products such as electrical appliances, consumer goods, industrial products, etc.
- The certification ensures that the product has undergone various tests and inspections to ensure its quality, durability, and safety.
- The ISI mark on a product indicates that it complies with the relevant Indian standards and quality parameters.

**2. Agmark Certification:**

- Agmark is a certification mark given by the Government of India to agricultural products.
- It ensures that the agricultural product meets the quality standards specified by the Agricultural Produce Grading and Marketing Act of 1937.
- Agmark certification is applicable to various agricultural commodities like grains, pulses, oilseeds, fruits, vegetables, spices, etc.
- The certification ensures that the product is of a certain quality, free from adulteration, and meets the specified standards.
- Agmark certification helps in building trust among consumers and promoting fair trade practices in the agricultural sector.

**3. Hallmark Certification:**

- Hallmark certification is given to precious metal products like gold, silver, and platinum.
- It ensures that the metal product meets the purity standards specified by the Bureau of Indian Standards (BIS).
- Hallmark certification provides assurance of the quality and purity of the precious metal.
- The certification includes testing and hallmarking of the metal product, which involves checking its purity, fineness, and other quality parameters.
- The Hallmark logo on a precious metal product guarantees its quality, genuineness, and adherence to the specified standards.

In conclusion, the logos of ISI, Agmark, and Hallmark on a product certify its quality standards. These certifications ensure that the product meets the specified quality parameters, safety requirements, and purity standards set by the respective authorities. Consumers can rely on these certifications to make informed decisions about the products they purchase, knowing that they meet the necessary quality standards.