The Butterfly Effect is a simple way to explain Chaos. The chaotic nature of cause and effect.

Quantum Entanglement is a bit difficult unless you read a lot of quantum theory.
Quantum basically means 'extremely small' (below nanoscale).
Physics are different in quantum.

In quantum scales, particles both exist and do not exist at the same time.
They are, in simple terms, everywhere and nowhere at the same time.

Entangled is a quantum state of a particle where it is present at two or more separate locations at the same time.
The cat is both alive and dead until you look.
quantum mechanics incorporates four classes of phenomena for which classical physics cannot account: quantization of certain physical properties. quantum entanglement. principle of uncertainty. wave–particle duality.
Quantum entanglement is the name given to a special connection between pairs or groups of quantum systems.

Quantum entanglement has been demonstrated experimentally with photons, neutrinos, electrons, molecules as large as buckyballs, and even small diamonds. On 13 July 2019, scientists from the University of Glasgow reported taking the first ever photo of a strong form of quantum entanglement known as Bell entanglement.

Basically you have a single particle which exists in at least two states at the same time. An action on one state affects the other with no mechanical chain of contact. It was termed a "Spooky" interaction by Albert Einstein.

It is possible to send information over a distance instantly using quantum entanglement. This is because what happens to one particle state also effects the other particle state.

Researchers in the Netherlands have just demonstrated that the quantum teleportation of information is now possible. For now, researchers are only quantum teleporting information a distance of ten feet, but conceivably, it means that larger objects can be transported even longer distances. - Jun 5, 2014
I recall reading about a more recent teleportation achievement where they teleported info to an orbiting satellite.
First Object Teleported from Earth to Orbit
Researchers in China have teleported a photon from the ground to a satellite orbiting more than 500 kilometers above.
by Emerging Technology from the arXiv
Jul 10, 2017
http://www.technologyreview.com/s/608252/first-object-teleported-from-earth-to-orbit/


Quantum computing uses spooky entanglement to transfer information instantly.
In quantum computing, a qubit (/ˈkjuːbɪt/) or quantum bit (sometimes qbit) is the basic unit of quantum information—the quantum version of the classical binary bit physically realized with a two-state device.

Think of two cards laying facedown on the table.
While they are face down, you have no idea what cards they are.
They might be two exact same cards (2 of clubs) or they may be two different cards.
They remain unknown (unchanged) until you flip them over.
In quantum entanglement you know they are both 2 of clubs but when you flip to look at one, the other dissapears instantly.
The act of looking initiates an instant change of state in the other because it is quantumly entangled with the card you look at.
The action on one causes a change in the other (it disappears).
Now imagine you still have two entangled cards except one card is in front of you and the other card is on the Moon.
You flip your card and the card on the Moon disappears.
When it disappears its absense is detected by someone on the Moon.
Information is sent to the Moon instantly via quantum entanglement.

With one entangled card you can tell someone on the Moon anything.
"When the card disappears, fire the cannon." or whatever.
The spooky entanglement might not have a range.
Meaning the same instant action can happen at any distance, Mars, Pluto, Proxima Centari, etc...

I use 'disappears as an example, the card on the Moon might not disappear, it might instantly change to be a 2 of clubs or whatever.
Erm, think of it as two punch cards with no holes.
Each punchcard has a grid of boxes on it.
You punch out a pattern on your punchcard and instantly the punchcard on the Moon exhibits the same pattern.
I believe its a bit more involved than that but it explains Quantum Entanglement in simplicity.

Two quantum computers could exchange information instantly between Earth and Mars.
This occurs because of Quantum Entanglement.