【Comfortable】 , 【cozy】 , 【snug】 , 【easy】 , 【restful】 are comparable when they mean enjoying or providing conditions or circumstances which make for one’s contentment and security.

【Comfortable】 usually implies the absence of whatever gives trouble, pain, or distress in any degree or of any kind to the body or mind, but it often applies to persons or things that encourage in one serenity of mind, tranquillity, a sense of well-being, or complacency.

【Cozy】 suggests comfortableness derived from warmth, shelter, ease, and friendliness.

【Snug】 (see also NEAT) suggests the state or the frame of mind of one who has as much room, or responsibility, or freedom, or money as is essential to his well-being but no more than he actually needs to be 【cozy】 , content, or secure; the term usually connotes such comfort as is associated with small but 【comfortable】  quarters as distinguished from those that are spacious or with a quiet, restricted, but pleasant way of life as distinguished from one where there is little time for one’s own interests or where one is driven by ambitions or restlessness; often, specifically, the term emphasizes protection from the elements, and warmth and dryness, as contributions to one’s comfort.

【Easy】 (see also 【EASY】 2) implies relief from all that makes for discomfort or hardships, with the result that one is happy or free from care, anxiety, trouble, or doubt.

【Restful】 usually suggests a state of mind of one who is 【comfortable】 ,  【cozy】 , or 【easy】 , as well as relaxed, or a quality in a thing that induces such a state of mind.