The differences of each type are listed below:

Sigma Bond:

1. The covalent bond formed by the overlap of atomic orbitals along the internuclear axis is called sigma bond

2. The overlapping orbitals are oriented along the internuclear axis.

3. s as well as p orbitals can form this type of bonds.

4. It is stronger than pi bond

Pi Bond:

1. The covalent bond formed by the lateral overlap of two p orbitals which are mutually parallel but oriented perpendicular to the internuclear axis is called the pi bond.

2. The overlapping orbitals are oriented perpendicular to the inter nuclear axis.

3. The bond is not rotationally symmetrical around the internuclear axis.

4. Only p orbitals can form this type of bond.