api ref: more impros to desc and examples of open and read

public/static/docs/api-reference/open.md

@@ -39,14 +39,14 @@ file can be tracked by DVC or by Git.
 [context manager](https://www.python.org/dev/peps/pep-0343/#context-managers-in-the-standard-library)
 (using the `with` keyword, as shown in the examples).
 
-> Use `dvc.api.read()` to get the complete file contents in a single function
-> call – no _context manager_ involved.
-
 This function makes a direct connection to the
 [remote storage](/doc/command-reference/remote/add#supported-storage-types)
-(except for Google Drive), so the file contents can be streamed as they are
-downloaded. No disc space and very little memory are needed to save the file
-before making it accessible.
+(except for Google Drive), so the file contents can be streamed. Your code can
+process the data [buffer](https://docs.python.org/3/c-api/buffer.html) as it's
+streamed, which optimizes memory usage.
+
+> Use `dvc.api.read()` to load the complete file contents in a single function
+> call – no _context manager_ involved. Neither function utilizes disc space.
 
 ## Parameters
 
@@ -90,9 +90,9 @@ before making it accessible.
 
 ## Example: Use data or models from DVC repositories
 
-Any <abbr>data artifact</abbr> hosted online can be employed directly in your
-Python app (no disc space needed) with this API. For example, an XML file
-tracked in a public DVC repo on Github can be processed like this:
+Any <abbr>data artifact</abbr> hosted online can be processed directly in your
+Python app with this API. For example, an XML file tracked in a public DVC repo
+on Github can be processed like this:
 
 ```py
 from xml.sax import parse

public/static/docs/api-reference/read.md

@@ -28,19 +28,17 @@ This function wraps [`dvc.api.open()`](/doc/api-reference/open), for a simple
 way to return the complete contents of a file tracked in a <abbr>DVC
 project</abbr>. The file can be tracked by DVC or by Git.
 
+> This is similar to the `dvc get` command in our CLI.
+
 The returned contents can be a
 [string](https://docs.python.org/3/library/stdtypes.html#text-sequence-type-str)
 or a [bytearray](https://docs.python.org/3/library/stdtypes.html#bytearray).
+These are loaded to memory directly (without using any disc space).
 
 > The type returned depends on the `mode` used. For more details, please refer
 > to Python's [`open()`](https://docs.python.org/3/library/functions.html#open)
 > built-in, which is used under the hood.
 
-> This is similar to the `dvc get` command in our CLI.
-
-No disc space is needed to save the file before loading it to memory in order to
-make the file accessible.
-
 ## Parameters
 
 - **`path`** - location and file name of the file in `repo`, relative to the
@@ -83,9 +81,9 @@ make the file accessible.
 
 ## Example: Load data from a DVC repository
 
-Any <abbr>data artifact</abbr> hosted online can be employed directly in your
-Python app (no disc space needed) with this API. For example, let's say that you
-want to load and unserialize a binary model from a repo on Github:
+Any <abbr>data artifact</abbr> hosted online can be loaded directly in your
+Python app with this API. For example, let's say that you want to load and
+unserialize a binary model from a repo on Github:
 
 ```py
 import pickle