Difference between two "types" of contraction

Question

Since Lorentz Contraction was proposed before Einstein's theory, the main explanation behind types of contraction proposed by both should be different. Is there any difference or one implies the other?

Answer 1

The proposal of length contraction by FitzGerald in 1889 and Lorentz in 1892 was purely ad hoc. They proposed it to round the failure of the Michelson–Morley experiment to detect any motion, however it was not based on any physical principles. Various attempts were made to justify it, but none with any success until Einstein developed special relativity.

Special relativity is based on a fundamental symmetry of spacetime called the invariance of the line interval (sometimes called the Lorentz interval). See How do I derive the Lorentz contraction from the invariant interval? for how length contraction can be obtained from this symmetry. So it wasn't until SR was formulated that we had a mechanism to explain length contraction.

Incidentally note that length contraction is not really a contraction but a rotation in spacetime. For more in this see my answer to "Reality" of length contraction in SR