Fresh describes things that are new or energetic, like fresh bread from the oven and fresh music from a recording artist. Moldy bread and grandpa's polkas? Not so fresh.
There are many uses for the adjective fresh, from being flirty to being well-rested. Ripe foods taste fresh compared to freezer-burned varieties, and fresh ideas are exciting and new. Fresh water is without the bitterness of salt water. Modern and different are also synonyms of fresh, while stale and tired are opposites.