There is no distinction. Under section 59 of the Succession Act 1925 every person who is sound mind and not being minor may dispose his property by will.

Section 59 of the Succession Act 1925 lays down that a person not being a minor but of sound mind dispose of property by will. The soundness is that of the mind and not of the body. Even a deaf of a dumb or blind person has the capacity of making a will, the only test is whether such person are able to know what they are doing.
A sound disposing mind means only the capacity to comprehend the nature and effect of the will which the person concerned is executing. what is to be considered is whether the deceased could understand the nature and effect of the particular documents which was being executed, the question to be considered is whether the deceased in a particular case was capable of appreciating that he was willing the whole of his self-acquired property to one of his sons and that he was depriving the other sons.

It is essential for the validity of a will that the testator should be of sound mind memory and understanding which means sound and disposing mind. A sound and disposing mind connotes that the testator must be conscious of the various claims person have upon his property and must also be capable of realizing the extent of the property disposed of under the will. It is essential that the testator at the time he signs the will be mentally competent to understand both these things. Where mind has been too much enfeebled by the illness or old age and infirmity arising from the approach of death the production of law is more needed and strong proof is requiring that the contents of the will were now to the testator and that it was his spontaneous act.