Nginx의 일반적인 기능은 무엇입니까?

#user nobody;
worker_processes 1;
#error_log logs/error.log;
#error_log logs/error.log notice;
#error_log logs/error.log info;
#pid  logs/nginx.pid;
events {
 worker_connections 1024;
}
http {
 include  mime.types;
 default_type application/octet-stream;
 #log_format main '$remote_addr - $remote_user [$time_local] "$request" '
 #     '$status $body_bytes_sent "$http_referer" '
 #     '"$http_user_agent" "$http_x_forwarded_for"';
 #access_log logs/access.log main;
 sendfile  on;
 #tcp_nopush  on;
 #keepalive_timeout 0;
 keepalive_timeout 65;
 #gzip on;
 server {
  listen  80;
  server_name localhost;
  #charset koi8-r;
  #access_log logs/host.access.log main;
  location / {
   root html;
   index index.html index.htm;
  }
  #error_page 404    /404.html;
  # redirect server error pages to the static page /50x.html
  #
  error_page 500 502 503 504 /50x.html;
  location = /50x.html {
   root html;
  }
  # proxy the php scripts to apache listening on 127.0.0.1:80
  #
  #location ~ \.php$ {
  # proxy_pass http://127.0.0.1;
  #}
  # pass the php scripts to fastcgi server listening on 127.0.0.1:9000
  #
  #location ~ \.php$ {
  # root   html;
  # fastcgi_pass 127.0.0.1:9000;
  # fastcgi_index index.php;
  # fastcgi_param script_filename /scripts$fastcgi_script_name;
  # include  fastcgi_params;
  #}
  # deny access to .htaccess files, if apache's document root
  # concurs with nginx's one
  #
  #location ~ /\.ht {
  # deny all;
  #}
 }
 # another virtual host using mix of ip-, name-, and port-based configuration
 #
 #server {
 # listen  8000;
 # listen  somename:8080;
 # server_name somename alias another.alias;
 # location / {
 #  root html;
 #  index index.html index.htm;
 # }
 #}
 # https server
 #
 #server {
 # listen  443 ssl;
 # server_name localhost;
 # ssl_certificate  cert.pem;
 # ssl_certificate_key cert.key;
 # ssl_session_cache shared:ssl:1m;
 # ssl_session_timeout 5m;
 # ssl_ciphers high:!anull:!md5;
 # ssl_prefer_server_ciphers on;
 # location / {
 #  root html;
 #  index index.html index.htm;
 # }
 #}
}

...    #全局块
events {   #events块
 ...
}
http  #http块
{
 ... #http全局块
 server  #server块
 { 
  ...  #server全局块
  location [pattern] #location块
  {
   ...
  }
  location [pattern] 
  {
   ...
  }
 }
 server
 {
  ...
 }
 ...  #http全局块
}

########### 每个指令必须有分号结束。#################
#user administrator administrators; #配置用户或者组，默认为nobody nobody。
#worker_processes 2; #允许生成的进程数，默认为1
#pid /nginx/pid/nginx.pid; #指定nginx进程运行文件存放地址
error_log log/error.log debug; #制定日志路径，级别。这个设置可以放入全局块，http块，server块，级别以此为：debug|info|notice|warn|error|crit|alert|emerg
events {
 accept_mutex on; #设置网路连接序列化，防止惊群现象发生，默认为on
 multi_accept on; #设置一个进程是否同时接受多个网络连接，默认为off
 #use epoll;  #事件驱动模型，select|poll|kqueue|epoll|resig|/dev/poll|eventport
 worker_connections 1024; #最大连接数，默认为512
}
http {
 include  mime.types; #文件扩展名与文件类型映射表
 default_type application/octet-stream; #默认文件类型，默认为text/plain
 #access_log off; #取消服务日志 
 log_format myformat '$remote_addr–$remote_user [$time_local] $request $status $body_bytes_sent $http_referer $http_user_agent $http_x_forwarded_for'; #自定义格式
 access_log log/access.log myformat; #combined为日志格式的默认值
 sendfile on; #允许sendfile方式传输文件，默认为off，可以在http块，server块，location块。
 sendfile_max_chunk 100k; #每个进程每次调用传输数量不能大于设定的值，默认为0，即不设上限。
 keepalive_timeout 65; #连接超时时间，默认为75s，可以在http，server，location块。
 upstream mysvr { 
  server 127.0.0.1:7878;
  server 192.168.10.121:3333 backup; #热备
 }
 error_page 404 https://www.baidu.com; #错误页
 server {
  keepalive_requests 120; #单连接请求上限次数。
  listen  4545; #监听端口
  server_name 127.0.0.1; #监听地址  
  location ~*^.+$ {  #请求的url过滤，正则匹配，~为区分大小写，~*为不区分大小写。
   #root path; #根目录
   #index vv.txt; #设置默认页
   proxy_pass http://mysvr; #请求转向mysvr 定义的服务器列表
   deny 127.0.0.1; #拒绝的ip
   allow 172.18.5.54; #允许的ip   
  } 
 }
}