In Java, both float and double are primitive data types used to represent floating-point numbers.
The main difference between them is their size and precision.
float is a 32-bit data type, which can represent values ranging from approximately 1.4e-45 to 3.4e38 with a precision of 6 to 7 decimal places.
double, on the other hand, is a 64-bit data type, which can represent values ranging from approximately 4.9e-324 to 1.8e308 with a precision of 15 decimal places.
Therefore, double has a wider range and higher precision than float. However, double requires twice as much memory as float to store the same amount of data.
In general, if you need to store large or precise decimal values, you should use double. If you're dealing with smaller numbers or don't need high precision, float can be a better choice since it requires less memory.