Type conversion in Java refers to the process of converting a value of one data type to another data type. This is also known as type casting. There are two types of type conversion in Java:

1. Implicit type conversion: This type of type conversion is done automatically by the Java compiler, without the need for any explicit instructions. It occurs when there is a widening of the data type, i.e. when the destination type is larger than the source type. For example, the assignment of an int value to a long variable is an example of implicit type conversion.
2. Explicit type conversion: This type of type conversion requires explicit instructions in the form of a cast operator. It occurs when there is a narrowing of the data type, i.e. when the destination type is smaller than the source type. For example, the assignment of a long value to an int variable requires an explicit type conversion using a cast operator.

To perform explicit type conversion in Java, you can use the cast operator, which is represented by the data type inside parentheses, followed by the value to be converted. For example, the following code shows how to perform explicit type conversion from a double value to an int value:

double d = 3.14; int i = (int)d;

It’s important to note that explicit type conversion can result in loss of precision or data, as the destination data type may not have sufficient space to hold the value of the source data type. Therefore, it’s always a good idea to carefully consider the potential consequences of explicit type conversion before using it in your code.