You may be wondering what a "mod" is. Without getting too technical, it is a simple way of saying a new way to play Counter Strike, ie. with added elements to the gameplay. This definition may be a bit hard to understand without examples, so, below listed are some of the more popular mods offered in CS 1.6. (A video to show these mods will most likely be released in the future)

KreedZ

AKA KZ, Climbing, Trickjump, Bunnyhopping, etc. KreedZ does not focus on the shooting element of CS, but rather jumping instead. It may sound childish and simple, but it is not. Jumpers have to weave around obstacles in midair, make a quick 180 jump around an obstacle, or even bunny hop through a map, something that the majority of CS players are unable to do due to its difficulty. While KZ'ing, you will learn about airstrafing, weapon speed, jump binds, and more.

Warcraft Mod

A mod in which players participate in rounds as usual, but have the option of choosing a "race" to play. The player must accumulate experience in order to gain levels and learn new abilities. These abilities range from running incredibly fast, to becoming nearly invisible, to even temporarily immobilizing an opponent of your choice. While playing, players can choose to purchase items at a shop menu screen. Many of these items can be useful such as an amulet that makes you completely silent while running, or a mask that lets you steal health from opposing team members.

Deathmatch

Deathmatches are simple: you spawn right away, you can choose whatever guns you want to use, and you keep going at it until you are killed. When you get killed, you respawn within seconds and have the ability to choose new weapons, or choose (and always automatically choose) the previous weapons you have used. Deathmatches are a good way to warm up and improve your aim before playing in a regular Counter Strike pub.

GunGame

Very similar to a Deathmatch, but you are not given any choice of weapons. Gungames (or GG's) can be played individually or in teams. In both types of GunGame, the object is to advance to the final level (usually the knife) and complete the level. You will usually start with a weak weapon and work your way up or a strong weapon and work your way down. In order to change guns and advance, you must eliminate X number of opposing team members, this depends on whether it is being played Solo or in Teams. If you are knifed (melee kill) you are downgraded to your previous weapon, while the person who knifed you is moved up a level automatically, regardless of how many more kills they needed. In team GG, the whole team has the same gun, and knife kills are not worth as much as they are in solo GG. (ie. They may be worth three shooting kills) In order to advance, there is usually a much higher number of kills needed to advance. (Depends on number of players)