Online poker is the game of poker played over the Internet. It has been partly responsible for a dramatic increase in the number of poker players worldwide.

Traditional or brick and mortar, live venues for playing poker, such as casinos and poker rooms, may be intimidating for novice players and are often located in geographically disparate locations. In addition, brick and mortar casinos are reluctant to promote poker because it is difficult for them to profit from it. Though the rake, or time charge, of traditional casinos is often high, the opportunity costs of running a poker room are even higher. Brick and mortar casinos often make much more money by removing poker rooms and adding more slot machines.

Online venues, by contrast, are dramatically cheaper because they have much smaller overhead costs. For example, adding another table does not take up valuable space like it would for a brick and mortar casino. Online poker rooms also allow the players to play for low stakes as low as 1¢/2¢ and often offer poker free roll tournaments where there is no entry fee, attracting beginners and/or less wealthy clientele.

Online venues may be more vulnerable to certain types of fraud, especially collusion between players. However, they have collusion detection abilities that do not exist in brick and mortar casinos. For example, online poker room security employees can look at the hand history of the cards previously played by any player on the site, making patterns of behavior easier to detect than in a casino where colluding players can simply fold their hands without anyone ever knowing the strength of their holding. Online poker rooms also check players' IP addresses in order to prevent players at the same household or at known open proxy servers from playing on the same tables

Typically, online poker rooms generate the bulk of their revenue via four methods. First, there is the rake. Rake is collected from most real money ring game pots. The rake is normally calculated as a percentage of the pot based on a sliding scale and capped at some maximum fee. Each online poker room determines its own rake structure. Since the expenses for running an online poker table are smaller than those for running a live poker table, rake in most online poker rooms is much smaller than its brick and mortar counterpart.

Second, hands played in pre-scheduled multi-table and impromptu sit-and-go tournaments are not raked, but rather an entry fee around five to ten percent of the tournament buy-in is added to the entry cost of the tournament. These two are usually specified in the tournament details as, e.g., $20+$2 $20 represents the buy-in that goes into the prize pool and $2 represents the entry fee, de facto rake. Unlike real casino tournaments, online tournaments do not deduct dealer tips and other expenses from the prize pool.

Third, some online poker sites also offer games like blackjack or side bets on poker hands where the player plays against the house for real money. The odds are in the house's favor in these games, thus producing a profit for the house. Some sites go as far as getting affiliated with online casinos, or even integrating them into the poker room software.

Fourth, like almost all institutions that hold money, online poker sites invest the money that players deposit. Regulations in most jurisdictions exist in an effort to limit the sort of risks sites can take with their clients' money. However, since the sites do not have to pay interest on players' bankrolls even low-risk investments can be a significant source of revenue.

Differences compared with conventional poker

There are substantial differences between online poker gaming and conventional, in-person gaming.

One obvious difference is that players do not sit right across from each other, removing any ability to observe others' reactions and body language. Instead, online poker players learn to focus more keenly on betting patterns, reaction time, speed of play, use of check boxes/auto plays, opponents' fold/flop percentages, chat box, waiting for the big blind, beginners' tells, and other behavior tells that are not physical in nature. Since poker is a game that requires adaptability, successful online players learn to master the new frontiers of their surroundings.

Another less obvious difference is the rate of play. In brick and mortar casinos, the dealer has to collect the cards, shuffle, and deal them after every hand. Due to this and other delays common in offline casinos, the average rate of play is around thirty hands per hour. However, online casinos do not have these delays. The dealing and shuffling are instantaneous, there are no delays relating to counting chips for a split pot, and on average, the play is faster due to auto-action buttons where the player selects his action before his turn. It is not uncommon for an online poker table to average ninety to one hundred hands per hour.

Online poker is considerably cheaper to play than conventional poker in many ways. While the rake structures of online poker sites might not differ fundamentally from those in brick and mortar operations, most of the other incidental expenses that are entailed by playing poker in a live room do not exist in online poker. An online poker player can play at home and thus incur no transportation costs to get to and from the poker room. Provided the player already has a somewhat modern computer and an Internet connection, there are no further up-front equipment costs to get started. There are also considerable incidental expenses once on a live poker table. In addition to the rake, tipping the dealers, chip runners, servers and other casino employees is almost universally expected, putting a further drain on a player's profits. Also, whereas an online player can enter and leave tables almost as he pleases, once seated at a live table a player must remain there until he wishes to stop playing, or else go back to the bottom of the waiting list. Food and beverages at casinos are generally expensive even compared to other hospitality establishments in the same city let alone compared to at home and casino managers feel little incentive to comp poker players.

Playing Cards

A playing card is a piece of specially prepared heavy paper, thin cardboard, or thin plastic, figured with distinguishing motifs and used as one of a set for playing card games. Playing cards are typically palm-sized for convenient handling.

A complete set of cards is called a pack or deck, and the subset of cards held at one time by a player during a game is commonly called a hand. A deck of cards may be used for playing a great variety of card games, some of which may also incorporate gambling. Because playing cards are both standardized and commonly available, they are often adapted for other uses, such as magic tricks, cartomancy, or building a house of cards.

The front or face of each card carries markings that distinguish it from the other cards in the deck and determine its use under the rules of the game being played. The back of each card is identical for all cards in any particular deck, and usually of a single color or formalized design. Usually every card will be smooth however some decks have braille to allow blind people to read the card number and suit. The back of playing cards is sometimes used for advertising. For most games, the cards are assembled into a deck, and their order is randomized by shuffling.