Yea for the most part they all end in ILD :p

WILD-Wake Induced, MILD-Mantra induced (I think), DILD (Dream induced), DEILD (Dream Exit Induced...like dreamchaining I think) and VILD-Visual Induced (technially goes with WILD or MILD because it's not it's own techinique). There are several tutorials on this site which are good and can go into much greater detail than I

I'll try to explain the stages of sleep but I'm no expert yet so it may be off :p

As we sleep we have different REM cycles, each longer than the last. After each cycle we briefly wake up but most do not recognize it and quickly fall back asleep. So during these waking periods if you recognize them you can wake up and write down what you remember, however you'll end up losing sleep this way. My method is just to simply wake up and write everything I can recall. Either way it's important that you write them down asap, some prefer not even sitting up :p Because once you get up and move around it's easy to forget it all.