Is a thoraco-lumbar spine AP&LAT And lumbo-sacral spine AP&LAT Is also a chest xray?? If not whats the diff??

It is not. A chest xray. The spine films use a narrower (collimated) xray beam so only the region of the spine is included. The part of the lungs next to the thoracic spine may be visualized, but most of the lungs and other structures of the chest wouldn't be seen. Also, the technique used for the spine is optimized to see bony structures, not lung tissue.
Different. A lumbosacral X-ray visualizes the lumbosacral spine, which is in the low back. A thoracolumbar X-ray shows the junction between the low and mid back. A chest X-ray shows the chest; which includes the lungs, the cardiac area, and the thoracic spine.
LS-spine is 4 bone- -detail, while chest X ray is 2 show soft tissue. If U used bone detail on the chest it would show the thoracic spine but not the soft tissue of the lumgs. Has 2 do with the power of the X ray settings to show what U want 2 C.