. . .. In Georgia, he was only concerned with hurting the South's military complex. If it had everything to do with their ability to wage war he destroyed it. If the local population absolutely depended on it to survive he left it. In South Carolina, however, he viewed them as the ones who started it all (which is absolutely true). In his mind they wouldn't have been fighting the war if South Carolina hadn't fired on Fort Sumter. So he pretty much told his army to "have at it" and had at it they did.
This generally true, but in South Carolina the destruction was much greater than Sherman envisioned. Military discipline at points completely broke down. The men had it in for South Carolina -- the mother of secession -- even more than did Sherman himself. Interestingly enough, as soon as Sherman's army crossed the border into North Carolina military disciple returned and destruction was again limited to things that could support the CSA's war machine. This meant railroad tracks, munition stores, arsenals, telegraph lines, some factories, etc. Private homes, except when unoccupied, were generally left alone.