Playing online games or applications is generally straightforward. Usually, for the normal functioning of such applications, you only need to properly configure and update some programs.
The easiest apps to use are online mini-games. You just need to choose a special site, register, and you can start the game. Many similar portals are even allowed to play with friends. Such applications do not require high speed from the Internet connection or high demands from the computer. But for these games to work correctly, you need to install a browser, for example, Mozilla Firefox, Opera, Google Chrome. In an old or even updated version of Internet Explorer, such games may not work or work incorrectly. They also require an updated version of the Adobe Flash Player (you need to download it here
Online browser games, which are more demanding than mini-games (a la fool, sapper, etc.), are also popular on the Internet. For correct operation, in addition to Adobe Flash Player and an updated browser, sometimes you have to download an additional network client. However, these games often require an internet connection speed of at least 512 kb / s.
When the games are not browser-based, but standard, then everything is different there. Sometimes, in order to join the game, you just need to enter the server ip-address into the console. But sometimes, in addition to this, you have to download an add-on, a patch, and maybe a network client. If there are any problems with entering the network mode for such games, then you should take a good look at the site with the add-on (for example, http://www.playground.ru) for patches to your game
If a "connection error" occurs when launching online games (non-browser ones), then most likely the problem is caused by an incorrectly configured antivirus or firewall. The security system simply prohibits the game from connecting to the server. To fix the situation, you need to add an "exception rule" to the firewall and add the game there.