TreeMap and LinkedHashMap are both implementations of the Map interface in Java, but they differ in the way they store and retrieve the key-value pairs.

TreeMap is a sorted map implementation that uses a red-black tree to store the keys in a sorted order. The keys must implement the Comparable interface, or an external Comparator must be provided. As a result, TreeMap provides guaranteed log(n) time cost for the containsKey, get, put, and remove operations. The drawback of TreeMap is that it does not maintain the insertion order of the keys.

Each entry in a LinkedHashMap maintains a pointer to the entry that comes before it and the entry that comes after it, which allows the entries to be ordered based on their insertion order or the order in which they were last accessed. The iteration order of the entries in a LinkedHashMap is determined by the order in which they were inserted or the order in which they were last accessed, depending on the constructor used to create the LinkedHashMap.