<s>
Little	B-Protocol
Snitch	I-Protocol
is	O
a	O
host-based	O
application	O
firewall	B-Application
for	O
macOS	B-Application
.	O
</s>
<s>
Unlike	O
a	O
stateful	O
firewall	B-Application
,	O
which	O
is	O
designed	O
primarily	O
to	O
protect	O
a	O
system	O
from	O
external	O
attacks	O
by	O
restricting	O
inbound	O
traffic	O
,	O
Little	B-Protocol
Snitch	I-Protocol
is	O
designed	O
to	O
protect	O
privacy	O
by	O
limiting	O
outbound	O
traffic	O
.	O
</s>
<s>
Until	O
Little	B-Protocol
Snitch	I-Protocol
4	O
,	O
it	O
controlled	O
network	O
traffic	O
by	O
registering	O
kernel	O
extensions	O
through	O
the	O
standard	O
application	B-Application
programming	I-Application
interface	I-Application
(	O
API	B-Application
)	O
provided	O
by	O
Apple	O
,	O
but	O
for	O
its	O
5th	O
release	O
it	O
switched	O
to	O
using	O
Apple	O
's	O
Network	O
Extensions	O
due	O
to	O
the	O
deprecationof	O
Kernel	O
Extensions	O
on	O
macOS	B-Device
Catalina	I-Device
.	O
</s>
<s>
If	O
an	O
application	O
or	O
process	O
attempts	O
to	O
establish	O
a	O
network	O
connection	O
,	O
Little	B-Protocol
Snitch	I-Protocol
prevents	O
the	O
connection	O
,	O
if	O
a	O
rule	O
for	O
that	O
connection	O
has	O
been	O
set	O
by	O
the	O
user	O
.	O
</s>
<s>
Little	B-Protocol
Snitch	I-Protocol
's	O
integral	O
network	O
monitor	O
shows	O
ongoing	O
traffic	O
in	O
real	O
time	O
with	O
domain	O
names	O
and	O
traffic	O
direction	O
displayed	O
.	O
</s>
