What are the differences between iso, sec, and tert-butyl groups in organic chemistry?

In organic chemistry, iso-, sec-, and tert-butyl groups are different types of alkyl groups attached to a carbon atom. The iso-butyl group has a branched structure with a methyl group attached to the second carbon atom, the sec-butyl group has a branched structure with a methyl group attached to the first carbon atom, and the tert-butyl group has a branched structure with three methyl groups attached to a central carbon atom. These differences in structure can affect the reactivity and properties of organic compounds containing these groups.