[Tutor] Is anyone capable of explaining ?

[A]

Can anybody please answer the following question?

Question: How does web browser know what cookies should be 
sent to server as a response?
For example I found out that a server sets 2 cookies

__cookie_client_data__=Uglv3rXE+d73YaYUuxoh/sDKsJ
t98itBb/hg2fFwFvHeEabkpKICibilujHZm

and

__cookie_temp_client_data__=aZNjw12D5JMrduWikHGk+
2pythOqr


but browser, as a response,sends only 
__cookie_temp_client_data__ 

Here is a part of communication between server 
and a client
##################first  SERVER #################

HTTP/1.1 200 OK - [54-68]
 Date: Mon, 04 Feb 2002 15:14:45 GMT - [71-105]
 Server: Apache/1.3.19 (Unix) Resin/1.1 - [108-
145]
 Cache-Control: no-cache="set-cookie,set-
cookie2" - [148-195]
 Expires: Thu, 01 Dec 1994 16:00:00 GMT - [198-
235]
 Set-Cookie: 
cookie_check=null;Path=/bin/user;Version=1 - 
[238-291]
 Set-Cookie: 
__cookie_client_data__=Uglv3rXE+d73YaYUuxoh/sDKsJ
t98itBb/hg2fFwFvHeEabkpKICibilujHZm ... - [294-
483]
104 - [294-484]
 Set-Cookie: 
__cookie_temp_client_data__=aZNjw12D5JMrduWikHGk+
2pythOqr

###########and CLIENT#################
----- HTTP Client Request ----- - [54-589]
[536 byte(s) of data]
 GET 
/html.ng/Site=English&Column=home&Category=/&BizN
ature=1&Province=&Position=1&Country=CZ&Ima ... -
 [54-189]
 Accept: image/gif, image/x-xbitmap, image/jpeg, 
image/pjpeg, application/vnd.ms-powerpoint, appl 
... - [192-332]
 Referer: http://www.alibaba.com/bin/user/signin 
- [335-381]
 Accept-Language: cs - [384-402]
 User-Agent: Mozilla/4.0 (compatible; MSIE 5.5; 
Windows 98; Win 9x 4.90) - [405-475]
 Host: ad3.alibaba.com - [478-498]
 Connection: Keep-Alive - [501-522]
65 - [501-523]
 Cookie: 
__cookie_temp_client_data__=aZNjw12D5JMrduWikHGk+
2pythOqr
################# end#################

Thank you for explanation.
Ladislav