The mass of the Perseverance rover is 1,025 kilograms. That makes it the heaviest rover ever sent to Mars at the time of its launch, with a mass comparable to a small car on Earth.
Perseverance is based partly on the successful design of Curiosity, but it carries a different scientific payload and a more ambitious sampling system. Its instruments are designed to study the geology and climate of Mars, identify potentially habitable ancient environments, and select rock samples for storage.
The 1,025-kilogram figure refers to the rover itself, not the entire spacecraft launched from Earth. The Mars 2020 spacecraft also included the cruise stage, aeroshell, heat shield, descent stage, and the Ingenuity helicopter. Those components were discarded or separated during the journey and landing.
A related source of confusion is the difference between mass and weight. Mass is measured in kilograms and remains the same wherever the object is located. Perseverance would weigh much less on Mars because Martian gravity is only about 38 percent of Earth's.