In general both equals() and “==” operator in Java are wont to compare objects to see equality but here are a number of the differences between the two:

1. Main difference between .equals() method and == operator is that one is method and other is operator.
2. We can use == operators for reference comparison (address comparison) and .equals() method for content comparison. In simple words, == checks if both objects point to an equivalent memory location whereas .equals() evaluates to the comparison of values within the objects.
    
3. If a category doesn't override the equals method, then by default it uses equals(Object o) method of the closest parent class that has overridden this method. See this for detail

Java and C are two popular programming languages, each with its own unique features and strengths. Here are some of the key differences between them:

1. Syntax: The syntax of Java and C are quite different. C uses a more concise syntax with fewer keywords, while Java has a more verbose syntax and many built-in classes.

2. Memory management: C allows for manual memory management, which can be more efficient but also more prone to errors. Java, on the other hand, uses automatic memory management through garbage collection, which can make it easier to write code but may result in slower performance.

3. Platform dependence: C is a low-level language and can be compiled to run on a wide range of platforms. Java, on the other hand, is designed to be platform-independent and can be run on any platform with a Java Virtual Machine (JVM).

4. Object-oriented programming: While both languages support object-oriented programming (OOP), Java is often seen as more of an OOP language, with features like inheritance and interfaces built into the language.

5. Applications: C is often used for low-level programming tasks like operating systems, device drivers, and embedded systems, while Java is popular for building web applications, mobile apps, and enterprise software.

In summary, C is a lower-level language with more control over memory and platform-specific features, while Java is a high-level, object-oriented language designed to be more portable and suitable for building larger-scale applications.