Differences between notochord and nerve cord are as follows
Notochord :
It is a solid ensheathed dorsal rod of large vacuolated cells.
It occurs in chordates.
It provides support and point of attachment to muscles.
In vertebrates, it forms the axial skeleton.
Nerve cord :
It is a bundle of nerve fibres with chains of ganglia, generally running ventrally
It occurs m invertebrates.
It gives rise to peripheral nerves.
It forms a major part of nervous system.