In My JavaCode , After clicking on Edit Description link a window get opens (i.e. Java Script Window) Images here 1st one gives anchor tag with attributes and 2nd one is opened
It is pretty clear from your snapshot that the window which gets opened is a JavaScript window i.e. an Alert. To enter some text into the Text Area and click Ok you can use the following block of code :
import org.openqa.selenium.Alert;
import org.openqa.selenium.By;
import org.openqa.selenium.support.ui.WebDriverWait;
import org.openqa.selenium.support.ui.ExpectedConditions;
//other code
Alert myAlert = new WebDriverWait(driver, 10).until(ExpectedConditions.alertIsPresent());
myAlert.sendKeys("I_am_bbk");
myAlert.accept();
driver.quit();