What does it mean when they say the universe is expanding

Is Universe Expanding?

Astronomy, Everyday Mysteries

PHYSICAL-SCIENCE-Q4-SLM17.pdf - Physical Science 11 Science - Grade 11 Quarter 4 - Module - 17: The Expanding Universe! Part 1 First Edition

ELI5 how fast is the universe expanding : r/explainlikeimfive

What exactly does it mean when you say the universe is 'expanding'? Does the planck-length get bigger? How can there be more space between objects? - Quora

What does it mean when they say the universe is expanding?

ELI5 how fast is the universe expanding : r/explainlikeimfive

What do we mean by the expansion of the universe? What is expanding? - Quora

What does the expansion of universe mean? - Quora

Is Universe Expanding?