Ojects and Class:

Object:
-> Java is an object-oriented programming language. The core concept of the object-oriented approach is to break complex problems into smaller objects.

-> An object is a real-word entity that has state and behaviour. In other words, an object is a tangible thing that can be touch and feel, like a car or chair, etc. are the example of objects.

-> The banking system is an example of an intangible object. Every object has a distinct identity, which is usually implemented by a unique ID that the JVM uses internally for identification.

Characteristics of an Object:

State: It represents the data (value) of an object.
Behavior: It represents the behavior (functionality) of an object such as deposit, withdraw, etc.
Identity: An object's identity is typically implemented via a unique ID. The ID's value is not visible to the external user; however, it is used internally by the JVM to identify each object uniquely.

Object Definitions:

• An object is a real-world entity.
• An object is a runtime entity.
• The object is an entity which has state and behavior.
• The object is an instance of a class.

["An object is an instance of a class. A class is a template or blueprint from which objects are created. So, an object is the instance(result) of a class."]

What is a Class in Java?
-> A class is a group of objects which have common properties. It is a template or blueprint from which objects are created. It is a logical entity. It can't be physical.

A class in Java can contain:

1. Fields

Variables stated inside a class that indicate the status of objects formed from that class are called fields, sometimes referred to as instance variables.
-> They specify the data that will be stored in each class object. Different access modifiers, such as public, private, and protected, can be applied to fields to regulate their visibility and usability.

2. Methods:

Methods are functions defined inside a class that includes the actions or behaviors that objects of that class are capable of performing.
-> These techniques allow the outside world to function and change the object's state (fields). Additionally, methods can be void (that is, they return nothing) or have different access modifiers. They can also return values.

Note:

["without class we cannot create object but the reverse is not true.without object we can create class "]

Reference:
-- https://www.javatpoint.com/object-and-class-in-java
-- https://www.programiz.com/java-programming/class-objects