Explain .Transform vs .ReplacementTransform in quickstart examples (#3500)

* Explained ReplacementTransform vs Transform

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* Added section explaining Transform vs ReplacementTransform

* Added a->b->c example

* Clarified explanation

* Fixed Typo

* Fixed missing colon

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---------

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Co-authored-by: Tristan Schulz <[email protected]>

Author: 3 people

docs/source/tutorials/quickstart.rst

@@ -268,11 +268,9 @@ and animating those method calls with ``.animate``.
 
            self.play(Create(square))  # show the square on screen
            self.play(square.animate.rotate(PI / 4))  # rotate the square
+           self.play(Transform(square, circle))  # transform the square into a circle
            self.play(
-               ReplacementTransform(square, circle)
-           )  # transform the square into a circle
-           self.play(
-               circle.animate.set_fill(PINK, opacity=0.5)
+               square.animate.set_fill(PINK, opacity=0.5)
            )  # color the circle on screen
 
 2. Render ``AnimatedSquareToCircle`` by running the following command in the command line:
@@ -293,8 +291,8 @@ The following animation will render:
 
            self.play(Create(square))  # show the square on screen
            self.play(square.animate.rotate(PI / 4))  # rotate the square
-           self.play(ReplacementTransform(square, circle))  # transform the square into a circle
-           self.play(circle.animate.set_fill(PINK, opacity=0.5))  # color the circle on screen
+           self.play(Transform(square, circle))  # transform the square into a circle
+           self.play(square.animate.set_fill(PINK, opacity=0.5))  # color the circle on screen
 
 The first ``self.play`` creates the square. The second animates rotating it 45 degrees.
 The third transforms the square into a circle, and the last colors the circle pink.
@@ -348,6 +346,55 @@ If you find that your own usage of ``.animate`` is causing similar unwanted beha
 using conventional animation methods like the right square, which uses ``Rotate``.
 
 
+``Transform`` vs ``ReplacementTransform``
+*****************************************
+The difference between ``Transform`` and ``ReplacementTransform`` is that ``Transform(mob1, mob2)`` transforms the points
+(as well as other attributes like color) of ``mob1`` into the points/attributes of ``mob2``.
+
+``ReplacementTransform(mob1, mob2)`` on the other hand literally replaces ``mob1`` on the scene with ``mob2``.
+
+The use of ``ReplacementTransform`` or ``Transform`` is mostly up to personal preference. They can be used to accomplish the same effect, as shown below.
+
+.. code-block:: python
+
+    class TwoTransforms(Scene):
+        def transform(self):
+            a = Circle()
+            b = Square()
+            c = Triangle()
+            self.play(Transform(a, b))
+            self.play(Transform(a, c))
+            self.play(FadeOut(a))
+
+        def replacement_transform(self):
+            a = Circle()
+            b = Square()
+            c = Triangle()
+            self.play(ReplacementTransform(a, b))
+            self.play(ReplacementTransform(b, c))
+            self.play(FadeOut(c))
+
+        def construct(self):
+            self.transform()
+            self.wait(0.5)  # wait for 0.5 seconds
+            self.replacement_transform()
+
+
+However, in some cases it is more beneficial to use ``Transform``, like when you are transforming several mobjects one after the other.
+The code below avoids having to keep a reference to the last mobject that was transformed.
+
+.. manim:: TransformCycle
+
+    class TransformCycle(Scene):
+        def construct(self):
+            a = Circle()
+            t1 = Square()
+            t2 = Triangle()
+            self.add(a)
+            self.wait()
+            for t in [t1,t2]:
+                self.play(Transform(a,t))
+
 ************
 You're done!
 ************