For installing the Java Development Kit, go back to the browser, open a new tab, and just search for jdk (short for Java Development Kit). This will bring you to the Oracle site, from where you can download Java:
On the Oracle website, click on JDK DOWNLOAD. Now, click on Accept License Agreement and then you can select the download option for your operating system:
For me, that's going to be Windows 64-bit and a wait for 198 MB of goodness to download:
Once the download is finished, we can't just accept ...