The Eagle lunar lander, carrying Armstrong and Aldrin, landed on the Sea of Tranquility on July 20, 1969. Armstrong was the first one out, proclaiming for the ages: “That's one small step for man, one giant leap for mankind.”

What is the meaning of Thats one small step for man one giant leap for mankind?

A phrase typically said in reference to a breakthrough or advancement of some kind. Astronaut Neil Armstrong famously said the phrase in 1969 when he became the first person to set foot on the moon.

What is the saying one small step for mankind?

The case also features Neil Armstrong's famous quote: the words he spoke when he became the first person to set foot on the Moon: "That's one small step for man, one giant leap for mankind."