Metroid Dread features a new technique in the Metroid series, and that is parrying. You will want to learn and perfect this technique for multiple reasons. Not only is it helpful in deflecting enemy attacks, but it also provides more resource drops from enemies.
To parry, you simply need to press the X button with the proper timing. You will typically know when to press this button when an enemy flashes gold as they attack. Most standard enemies have a generous time window to parry, but unfortunately, the same cannot be said of the E.M.M.I.
This enemy can instakill you if it manages to grab ahold of you. Once it does, you will have two opportunities to escape its grasp. When it first grabs you and right before its thrusts its needle, you can parry it. The timing on these is incredibly precise to the point where you almost need to press X right before the flash appears.
Learning to parry can save your life numerous times and keep you stocked up on energy and missiles. Some bosses also have attacks you can parry that otherwise would deal a lot of damage. After parrying an E.M.M.I. you will have a brief moment to slide under its legs and run away.