Keyword Analysis & Research: what does using namespace std mean in c

Keyword Analysis

Keyword	CPC	PCC	Volume	Score	Length of keyword
what does using namespace std mean in c	1.42	1	8243	79	41
what	1.74	0.5	2272	24	4
does	1.93	0.9	4965	27	4
using	1.35	0.3	646	99	5
namespace	1.47	0.9	1172	81	9
std	1.76	1	2068	82	3
mean	1.63	1	4012	80	4
in	1.26	0.9	1277	17	2
c	0.38	0.9	7105	42	1

Keyword	CPC	PCC	Volume	Score
what does using namespace std mean in c	2	0.8	1278	21