EULA is a contractual document. We are talking about a contract of adhesion as opposed to the negotiated contract. The user of the service chooses to accept or reject them but does not negotiate their content with the service operator. Like any contractual documents, the general conditions of use commit the user of the service and its operator to respect the content.
Use of TOU/TOS/EULA on the Internet
In many countries other than United States, EULAs for standard software are only part of the contract if they have already been agreed between the seller and the purchaser of the software at the time of purchase. This presupposes the possibility of acknowledgment at the time of conclusion of the contract. License terms made available to the buyer only after purchase (for example, during installation or as a printed insert in the packaging) are ineffective for the buyer. This is true even if the buyer agrees to the license agreement or similar statements at the time of installation, if the software otherwise refuses to install (which it usually does).
Even if the license terms were agreed at the time of purchase (for example, in the case of online purchase by means of a clearly visible text before the purchase or in the case of purchase in a physical store by clearly recognizable printing of the full conditions on the packaging), their effectiveness may be limited. They then represent general terms and conditions that are subject to content control by the general terms and conditions regulations.
The majority of websites have general conditions of use. Their contents detail the general functioning of the site, the terms of its use and the rules to be respected by its users. They result in a dedicated window or web page submitted to the reading and appreciation of the user when registering or participating in the site. Their acceptance is most often done through a checkbox.
The general conditions of use including TOU, TOS govern the use of a service. The general conditions of sale frame a commercial relationship. On the internet, the general conditions of use can be used on commercial sites as well as on non-commercial sites, their purpose being to regulate the use of the site. They are not a legal obligation. On the other hand, the general conditions of sale are of interest only on commercial sites, their purpose being to frame a commercial relationship. They are a legal obligation on all merchant sites.