Web traffic is a certain amount of data that pass through the server. Traffic can be incoming or outgoing. Incoming traffic is the amount of information which is sent to the server. Outgoing traffic is the data processed by a server and sent to the user. It can be calculated by kilobytes, megabytes, gigabytes or number of visitors on a site.

Internet is a global network which provides possibility of storage and a data interchange worldwide. Information is transferred in a digital form and can be available round the clock all over the world. The most popular services on the Internet are websites (forums, blogs, web-stores), e-mail, file hosting services, payment systems, search engines, radio, TV etc.

Dedicated server is a rental service of a physical server in the data center. The client leases specific physical server hardware and does not shared with anyone else. Unlike a VDS, the owner of a physical dedicated server has full access not only to the software but also to the hardware resources.

VDS is a Virtual Dedicated Server. It is same as the VPS. VDS provides additional safety for a website.

Server is a repository for files, data and other information. Usually a server is a powerful computer connected to the network. With the help of the server software it communicates with the client (user's computer or other device) and allows it to handle client requests and send the information to the user.

Server log is a file which contains information on server operation. It allows receiving detailed reports in which all actions of visitors of a site are reflected. Analysis of users behavior, popularity of these or those pages, etc. is carried out based on similar reports.

HTTP cookies are the files, which contain a small amount of information about a particular web resource. Files can be stored in the computer memory. There are session cookies (remain in a random access memory) and persistent cookies (register in a hard drive). They allow to process requests from the browser of the user much quicker.

CMS is a content management system. Main function of CMS is simplifying the site administration. Thanks to the CMS, any user can edit, add and delete material from the site. When using a CMS website structure does not look like a set of static html-pages. It has the form of structured database. Due to this a performance of a web site increases.

Account can be created by any user on the network, where user enters his login, password and personal information. Registration is necessary on many sites, especially on the web stores that contain information about the customer's accounts, his purchases and other data.

Webrating is a tool for monitoring of site attendance. It automatically counts number of unique visitors and total number of visitors for different time frames (day, week, month and so on). It also makes statistics on which it is possible to see efficiency of forces and finance spent for website promotion.