<s>
Google	B-Application
APIs	I-Application
are	O
application	O
programming	O
interfaces	O
(	O
APIs	B-General_Concept
)	O
developed	O
by	O
Google	B-Application
which	O
allow	O
communication	O
with	O
Google	B-Application
Services	I-Application
and	O
their	O
integration	O
to	O
other	O
services	O
.	O
</s>
<s>
Examples	O
of	O
these	O
include	O
Search	O
,	O
Gmail	O
,	O
Translate	O
or	O
Google	B-Application
Maps	O
.	O
</s>
<s>
Third-party	O
apps	O
can	O
use	O
these	O
APIs	B-General_Concept
to	O
take	O
advantage	O
of	O
or	O
extend	O
the	O
functionality	O
of	O
the	O
existing	O
services	O
.	O
</s>
<s>
The	O
APIs	B-General_Concept
provide	O
functionality	O
like	O
analytics	O
,	O
machine	O
learning	O
as	O
a	O
service	O
(	O
the	O
Prediction	O
API	B-General_Concept
)	O
or	O
access	O
to	O
user	O
data	O
(	O
when	O
permission	O
to	O
read	O
the	O
data	O
is	O
given	O
)	O
.	O
</s>
<s>
Another	O
important	O
example	O
is	O
an	O
embedded	O
Google	B-Application
map	O
on	O
a	O
website	O
,	O
which	O
can	O
be	O
achieved	O
using	O
the	O
Static	O
Maps	O
API	B-General_Concept
,	O
Places	O
API	B-General_Concept
or	O
Google	B-Application
Earth	O
API	B-General_Concept
.	O
</s>
<s>
Usage	O
of	O
all	O
of	O
the	O
APIs	B-General_Concept
requires	O
authentication	O
and	O
authorization	O
using	O
the	O
Oauth	O
2.0	O
protocol	O
.	O
</s>
<s>
Then	O
the	O
client	O
app	O
can	O
request	O
an	O
access	O
Token	O
from	O
the	B-Application
Google	I-Application
Authorization	O
Server	O
,	O
and	O
uses	O
that	O
Token	O
for	O
authorization	O
when	O
accessing	O
a	O
Google	B-Application
API	B-General_Concept
service	O
.	O
</s>
<s>
There	O
are	O
client	O
libraries	O
in	O
various	O
languages	O
which	O
allow	O
developers	O
to	O
use	O
Google	B-Application
APIs	I-Application
from	O
within	O
their	O
code	O
,	O
including	O
Java	B-Language
,	O
JavaScript	B-Language
,	O
Ruby	B-Language
,	O
.NET	B-Application
,	O
Objective-C	B-Language
,	O
PHP	B-Application
and	O
Python	B-Language
.	O
</s>
<s>
The	B-Application
Google	I-Application
Loader	O
is	O
a	O
JavaScript	B-Language
library	O
which	O
allows	O
web	O
developers	O
to	O
easily	O
load	O
other	O
JavaScript	B-Language
API	B-General_Concept
provided	O
by	O
Google	B-Application
and	O
other	O
developers	O
of	O
popular	O
libraries	O
.	O
</s>
<s>
Google	B-Application
Loader	I-Application
provides	O
a	O
JavaScript	B-Language
method	O
for	O
loading	O
a	O
specific	O
API	B-General_Concept
(	O
also	O
called	O
module	O
)	O
,	O
in	O
which	O
additional	O
settings	O
can	O
be	O
specified	O
such	O
as	O
API	B-General_Concept
version	O
,	O
language	O
,	O
location	O
,	O
selected	O
packages	O
,	O
load	O
callback	O
(	O
computer	O
programming	O
)	O
and	O
other	O
parameters	O
specific	O
to	O
a	O
particular	O
API	B-General_Concept
.	O
</s>
<s>
Dynamic	O
loading	O
or	O
auto-loading	O
is	O
also	O
supported	O
to	O
enhance	O
the	O
performance	O
of	O
the	O
application	O
using	O
the	O
loaded	O
APIs	B-General_Concept
.	O
</s>
<s>
Google	B-Application
Apps	I-Application
Script	O
is	O
a	O
cloud-based	B-Architecture
JavaScript	B-Language
platform	O
which	O
allows	O
developers	O
to	O
write	O
scripts	O
only	O
owner	O
can	O
manipulate	O
API	B-General_Concept
services	O
such	O
as	O
Calendar	O
,	O
Docs	O
,	O
Drive	O
,	O
Gmail	O
,	O
and	O
Sheets	O
and	O
easily	O
create	O
Add-Ons	O
for	O
these	O
services	O
with	O
chromium	O
based	O
applications	O
.	O
</s>
<s>
User	O
registration	O
is	O
commonly	O
done	O
via	O
Google	B-Application
,	O
which	O
allows	O
users	O
to	O
securely	O
log	O
into	O
third-party	O
services	O
with	O
their	O
Google	B-Application
account	O
through	O
the	B-Application
Google	I-Application
Sign-in	O
system	O
.	O
</s>
<s>
This	O
is	O
currently	O
available	O
from	O
within	O
Android	B-Application
(	O
operating	O
system	O
)	O
or	O
by	O
using	O
JavaScript	B-Language
.	O
</s>
<s>
It	O
is	O
popular	O
to	O
include	O
a	O
"	O
Sign	O
in	O
with	O
Google	B-Application
"	O
button	O
in	O
Android	B-Application
apps	O
,	O
as	O
typing	O
login	O
credentials	O
manually	O
is	O
time-consuming	O
due	O
to	O
the	O
limited	O
screen	O
size	O
.	O
</s>
<s>
As	O
the	O
user	O
is	O
usually	O
signed	O
into	O
their	O
Google	B-Application
account	O
on	O
their	O
mobile	O
device	O
,	O
signing-in/signing	O
-up	O
for	O
a	O
new	O
service	O
using	O
a	O
Google	B-Application
account	O
is	O
usually	O
a	O
matter	O
of	O
a	O
few	O
button	O
clicks	O
.	O
</s>
<s>
Drive	O
apps	O
are	O
various	O
web	O
applications	O
which	O
work	O
within	O
Google	B-Application
Drive	O
using	O
the	O
Drive	O
API	B-General_Concept
.	O
</s>
<s>
Users	O
can	O
integrate	O
these	O
apps	O
into	O
their	O
Drive	O
from	O
the	O
Chrome	O
Web	O
Store	O
,	O
allowing	O
them	O
to	O
work	O
entirely	O
in	B-Architecture
the	I-Architecture
cloud	I-Architecture
.	O
</s>
<s>
There	O
are	O
many	O
apps	O
available	O
for	O
collaborative	O
document	O
editing	O
(	O
Google	B-Application
Docs	O
,	O
Sheets	O
)	O
,	O
picture/video	O
editing	O
,	O
work	O
management	O
,	O
or	O
sketching	O
diagrams	O
and	O
workflows	O
.	O
</s>
<s>
Custom	O
Search	O
allows	O
web	O
developers	O
to	O
provide	O
a	O
search	O
of	O
their	O
own	O
website	O
by	O
embedding	O
a	O
custom	O
search	O
box	O
and	O
using	O
the	O
Custom	O
Search	O
API	B-General_Concept
.	O
</s>
<s>
App	O
Engine	O
are	O
web	O
apps	O
that	O
run	O
on	O
the	B-Application
Google	I-Application
App	O
Engine	O
,	O
a	O
platform-as-a-service	B-Application
(	O
PaaS	B-Application
)	O
cloud	B-Architecture
computing	I-Architecture
platform	I-Architecture
which	O
allows	O
web	O
developers	O
to	O
run	O
their	O
websites	O
in	O
Google	B-Application
datacenters	O
.	O
</s>
<s>
These	O
web	O
apps	O
cannot	O
take	O
advantage	O
of	O
APIs	B-General_Concept
to	O
manipulate	O
services	O
such	O
as	O
TaskQueue	O
(	O
a	O
distributed	O
queue	O
)	O
,	O
BigQuery	O
(	O
a	O
scalable	O
database	O
based	O
on	O
Dremel	O
)	O
or	O
DataStore	O
.	O
</s>
<s>
Gadgets	O
are	O
mini-applications	O
built	O
in	O
HTML	B-Language
,	O
JavaScript	B-Language
,	O
Adobe	B-Operating_System
Flash	I-Operating_System
and	O
Silverlight	B-Application
that	O
cannot	O
be	O
embedded	O
in	O
webpages	O
and	O
other	O
apps	O
.	O
</s>
