What makes Strong nuclear and weak nuclear different?

It sounds like you are referring to the universal forces. The 'Nuclear Force' refers to two of the four known universal forces (the others are gravity and electromagnetism).

The 'Strong Nuclear Force' (SNF) refers to the force that holds the atomic nucleus together against the electromagnetic force of repulsion caused by the positively charged protons. The force carrier particles for the SNF are the gluon particles.

The 'Weak Nuclear Force' (WNF) refers to the force that causes radioactive decay of 'unstable' atomic nuclei. The force carrier particles for the WNF are the w+, w-, and z0 particles.


- All according to the [Standard Model] of physics.