Enantiomers
These are two identical models of ethyl chloride, oriented as mirror images

R-1-bromo-1-chloroethane S-1-bromo-1-chloroethane

R-3-chloro-1,2-propanediol S-3-chloro-1,2-propanediol
R-carvone S-carvone
R-thalidomide S-thalidomide

Diastereomers

2R,3R-Threonine

2S,3S-Threonine

2R,3S-Threonine

2S,3R-Threonine

Meso Compounds

D(+)-Tartaric acid

L(-)-Tartaric acid

Meso-Tartaric acid

Meso-Tartaric acid