Ultimately this comes down to a question on romanization. Pinyin is a romanization system for Chinese.
There are a few different systems of romanization for Korean. The two most prevalent are McCune–Reischauer (M-R) and Revised Romanization of Korean (RR). Revised Romanization is what is used in South Korea officially now (it replaced M-R in 2000). The main difference between M-R and RR is the use of diacritics like the breve and the apostrophe. (i.e. 저 is written chŏ in M-R, yet jeo in RR. 창 is written ch'ang in M-R and chang in RR). RR uses no diacritics and is built to ostensibly represent phonology better. M-R is constructed to perhaps better capture Korean phonetics. Neither is perfect.
Google translate uses a variant of RR, since this is usually easier for non-native speakers to understand. If you know all the rules of RR, you can usually quite easily "translate" from the romanized output of Google translate to actual 한글 (hangŭl [M-R], hangeul [RR]). However, keep in mind that romanized Korean is the absolute lowest order form of conveying written Korean.