List
<ul>
<li>ArrayList
<ul>
<li>It internally uses an array
</li>
<li>Fast to access the elements by index
</li>
<li>Slower if you want to do operations in the middle
</li>
</ul>
</li>
<li>LinkedList
<ul>
<li>Based on a Double Linked
</li>
<li>Very fast for deleting or adding elements in the middle
</li>
</ul>
</li>
<li>Vector
<ul>
<li>It belongs to the legacy
</li>
<li>Synchronized
</li>
</ul>
</li>
<li>Stack
<ul>
<li>It basically implements a stack.</li>
</ul>
</li>
</ul>
Queue
<ul>
<li>PrioritQueue
<ul>
<li>Implements a Queue</li>
</ul>
</li>
<li>ArrayDeque
<ul>
<li>Implements a Queue, but allows us to do operations at the bottom and at the top</li>
</ul>
</li>
</ul>
Set
<ul>
<li>HashSet
<ul>
<li>Doesn't allow duplications
</li>
<li>Doesn't keep the order of insertion
</li>
</ul>
</li>
<li>LinkedHashSet(Log(1))
<ul>
<li>Keep the order of insertion</li>
</ul>
</li>
<li>TreeSet(Log(n))
<ul>
<li>It sorts the elements using the natural order</li>
</ul>
</li>
</ul>
Map
<ul>
<li>HashMap
<ul>
<li>Unsorted keys
</li>
<li>A pair of keys and values.
</li>
<li>Allows null values at the key
</li>
</ul>
</li>
<li>LinkedHashMap
<ul>
<li>Maintain the insertion order</li>
</ul>
</li>
<li>HashTable
<ul>
<li>The same as HashMap, but it is synchronized
</li>
<li>Slower than HashMap
</li>
<li>Belongs to the legacy of Java. Try to not use this
</li>
</ul>
</li>
<li>TreeMap
<ul>
<li>The key is sorted using the natural order of the Keys.
</li>
<li>Also, you can implement your own sort order
</li>
</ul>
</li>
</ul>

**List**

* ArrayList
    
    * It internally uses an array
        
    * Fast to access the elements by index
        
    * Slower if you want to do operations in the middle
        
* LinkedList
    
    * Based on a Double Linked
        
    * Very fast for deleting or adding elements in the middle
        
* Vector
    
    * It belongs to the legacy
        
    * Synchronized
        
* Stack
    
    * It basically implements a stack.
        

**Queue**

* PrioritQueue
    
    * Implements a Queue
        
* ArrayDeque
    
    * Implements a Queue, but allows us to do operations at the bottom and at the top
        

**Set**

* HashSet
    
    * Doesn't allow duplications
        
    * Doesn't keep the order of insertion
        
* LinkedHashSet(Log(1))
    
    * Keep the order of insertion
        
* TreeSet(Log(n))
    
    * It sorts the elements using the natural order
        

**Map**

* HashMap
    
    * Unsorted keys
        
    * A pair of keys and values.
        
    * Allows null values at the key
        
* LinkedHashMap
    
    * Maintain the insertion order
        
* HashTable
    
    * The same as HashMap, but it is synchronized
        
    * Slower than HashMap
        
    * Belongs to the legacy of Java. Try to not use this
        
* TreeMap
    
    * The key is sorted using the natural order of the Keys.
        
    * Also, you can implement your own sort order

Java Collections