In a nutshell, articulation is basically tonguing a note on the saxophone. There is stopping the airflow and continuing the airflow. This is tonguing a note on the saxophone with the airflow interrupted. You hear the air stop. This is articulating or tonguing the note with the airflow continued, where you're actually stopping the reed with your tongue about here, without stopping the airflow. You can hear the air continue but the note is starting and stopping because I'm controlling the reed not the air.
When we apply this to scales, here is a D major scale on the alto saxophone not articulated. Another word for that is slurred. Here it is, the same thing again, all articulated. The air flow continued, which is how you want to play scales. Staccato is a different thing where you stop the air. A D major scale staccato would be like this. We can continue this exercise with major scales by tonguing every second note, which is also referred to as back-tonguing, and that sounds like this. That's really helpful when playing fast, as opposed to slurred.
Another tonguing technique is commonly used and I have a lot of students ask me about slap tonguing, which is hard to explain, but much like riding a bicycle once you've got it, you'll always have it. It's almost like honking out a low note, the way you would place your embouchure to do that, but not following through with the air. Instead of, we've got. The way you articulate that note down there. If you were to apply that to the other notes and not follow through with any air, you've essentially got slap tonguing. That's a cool little gimmick you can use for something funky like.
That's articulation for the saxophone.