It's difficult to understand what Samsara is, as all sentient beings are immersed in it. Samsara is everything we know, everything we do, everything we hear, everything we see. Samsara is a Sanskrit word that, when translated into english, means an endless circle.
We all constantly strive to find permanent happiness and contentment. Considering that Samsara includes both the highest level of existence and the lowest, all sentient beings do their best to avoid suffering, from gods to the beings in the deepest hells.
Regarding human beings, everyone desires not only their own happiness but also the prosperity and well-being of their loved ones and friends, whom they do not want to see suffer in any way.
Throughout life, one can achieve some satisfaction and moments of joy, thereby avoiding affliction for some time, but it is almost impossible to fully escape suffering and attain lasting inner happiness.
Human beings focus a large part of their efforts and resources on acquiring material well-being, believing that by doing so, they will live with greater fulfillment and enthusiasm. They build and invent all kinds of gadgets to feel happy and safe, to escape fear and suffering, and in the pursuit of lasting happiness.