There are several different VOCALOID Editors you can use to make VOCALOID songs. Currently, I own the digital versions of the VOCALOID4 Editor and the Tiny VOCALOID3 Editor.
The VOCALOID4 Editor is the version of the VOCALOID Editor for VOCALOID4 and VOCALOID3 voice banks. If you have a VOCALOID4 or VOCALOID3 voice bank installed on your computer, you can use the VOCALOID4 Editor to create a song by entering a melody and lyrics. You can buy the VOCALOID4 Editor here.
Here are some new functions of VOCALOID4:
The VOCALOID4 Editor costs 10,000 Yen (About 90 Dollars). The VOCALOID4 Editor can only be used on Windows 10, Windows 8.1, Windows 8, and Windows 7. If you do not own a Windows computer, you can use the VOCALOID4 Editor for Cubase or Piapro Studio.
The Tiny VOCALOID3 Editor (Sometimes called the VOCALOID3 Editor Lite) is a version of the VOCALOID3 Editor that comes with VOCALOID3 voice banks. You can only enter 17 measures in each song. For a list of all the differences, go to this website. The Tiny VOCALOID3 Editor can only be used on Windows. If you buy a VOCALOID3 voice bank and install it on a Mac, the voice bank will not come with the Tiny VOCALOID3 Editor.
A VOCALOID Starter Pack is a bundle of a VOCALOID voice bank and the VOCALOID3 or VOCALOID4 Editor. Not all voice banks have Starter Packs, but most Starter Packs are less expensive than buying a voice bank and the editor separately. You can buy some of the VOCALOID Starter Packs here.