편하다: convenient and comfortable. 안락하다: safe (안: 安) and pleasant (락: 樂) They are both adjectives sharing the sense of "comfortable". The main difference is that 편하다 is used very widely while 안락하다 is mostly used in writings. 편하다 is wider in meaning too, used both for physical and psychological comfort. Its antonym, 불편하다, is also very widely used to mean inconvenient/uncomfortable. 안락하다 is only used for physical comfort, a sojourn or a lifestyle, and rarely for anything psychological. ex) 이 동네는 참 살기(가) 편하다: This town is nice and convenient to live in. 일을 끝마치니까 마음이 편하다: I feel comfortable now that I have finished my work. 편한 세상이다: It is a convenient world. 안락한 전원 생활: comfortable country life.