What are the differences between sputnik 1 and sputnik 2?

Sputnik 1, launched on October 4, 1957, was the first artificial satellite to orbit the Earth, transmitting radio signals back to Earth. In contrast, Sputnik 2, launched on November 3, 1957, carried the first living creature into space, a dog named Laika, and included more advanced instrumentation for scientific research. While Sputnik 1 was primarily a demonstration of satellite technology, Sputnik 2 aimed to study the biological effects of space travel on living organisms. Additionally, Sputnik 2 was significantly heavier and larger than its predecessor.