I am new to doctrine, In my symfony project all the entity annotation linked with groups but **I am not getting what is the use of Groups.**

```
/**
     * @ORM\Column(type="string", length=64)
     * @Groups({"public","details"})
     */

```

I have newly added the field in my entity file, while executing the schema update getting (newly added field) was never imported.

What is groups and how it's useful.