Are declared in a class, but outside a method, constructor or any block.
When a space is allocated for an object in the heap, a slot for each instance variable value is created.
Are created when an object is created with the use of the keyword 'new' and destroyed when the object is destroyed.
Can be declared in class level before or after use.
Access modifiers can be given for instance variables.
Are visible for all methods, constructors and block in the class. Normally, it is recommended to make these variables private (access level). However, visibility for subclasses can be given for these variables with the use of access modifiers.
Have default values. For numbers, the default value is 0, for Booleans it is false, and for object references it is null. Values can be assigned during the declaration or within the constructor.
Can be accessed directly by calling the variable name inside the class. However, within static methods, they should be called using the fully qualified name. ObjectReference.VariableName.