What are the differences between E1 and E2 reactions?

Hi dear friend!

For E1:

1- unimolecular reaction, rate of reaction depends on the concentration of substrate or alkyl halid. 2- it does not require strong base, attacking group. 3- tertiary alkyl halide favors E1 mostly.

For E1:

1- bimolecular reaction, rate of reaction depends on the concentration of substrate or alkyl halid as well as base or attacking nucleophile. 2- it requires strong base, nucleophile. 3- Primary alkyl halide favors E2 mostly.