Compounds of carbon, which are linked by only single bonds between the carbon atoms are called [[1]]compounds and those having more than one between their carbon atoms are called [[2]] compounds. 

Carbon has the tendency to form strong and stable bonds with similar atoms. When all the four valencies of carbon are satisfied with single bonds with other atoms, it is referred to as saturated whereas when any double or triple bond is formed by carbon, it is referred to as unsaturated.