Vertcoin was originally forked from Litecoin. When scrypt ASICs were developed Vertcoin opted to change its mining algorithm and remain ASIC resistant for the sake of decentralization. It foresaw the issues ASICs would bring into the crypto-space (BCH, BTC, Segwit2x) and wanted to allow everyone the ability to mine the coin and not just a select few.
VTC was also the first crypro currency to ever introduce a Stealth Address feature. It's currently being re-implemented but it's designed specifically for businesses or individuals to perform transactions without revealing wallet address or historic transactions - a feature LTC does not have.