How do jet streams differ from winds in the lower atmosphere?

Wind is caused by a pressure gradient. Air moves from areas of high pressure to areas of low pressure. The Coriolis effect (effect of the Earth's rotation) deflects these winds so that the air moves between the areas of high pressure to areas of low pressure.

The boundary layer of the atmosphere (about the first 3000ft) is influenced by contact with the surface of the Earth. As such the wind is slowed by friction and since it is slowed the Coriolis effect becomes lessened. The air moves slowly into areas of low pressure, slowly filling them, and high pressures will slowly weaken.

So the difference between wind in the lower atmosphere and the upper atmosphere is speed and direction changes cause by friction due to contact with the surface of the Earth.

Since jet streams can occur in both upper air and lower air, your question as worded doesn't seem like what you are asking. If you want to know about jet streams please let me know.