In electronic data processing (EDP), downloading is the receiving of data on one's own computer , the client , which originates from a server via a network , usually the Internet . The data itself that is transmitted or made available for transmission is also referred to as a download. In contrast to calling up a website or streaming a video , the goal and result of a download is the permanent storage of the data downloaded, usually a single file, on the user's device. Downloading or downloading is the opposite of uploading or uploading .
Since the widespread use of fast Internet connections , downloads have played an increasingly important role in the commercial distribution and private exchange of digital goods such as software , music , films and e-books . In addition, downloads of many types of documents have largely supplanted the previously common distribution in paper form, for example technical documentation , industry standards and norms , product catalogues , scientific studies and larger user manuals .
The basic principle of downloading is to actively request one or more files that are offered or made available for download by a provider and then to receive and save them on your own device. The device that receives the data is often a personal computer , smartphone or tablet computer .
On the other hand, the basic principle of uploading is that the provider actively sends (“uploads”) one or more files from their own device to a remote station, which receives the files. The receiving remote station is often a server or host .
The file transfer protocol FTP , existing since 1985, serves as an Internet protocol (IP) for downloading and uploading files as well as a number of special applications. However, when data is downloaded from a website on the World Wide Web , the FTP is interrupted to ask the user for the desired storage location. After confirming the save location, the transfer will continue.
The communication protocol HTTPS is a secure hypertext transmission protocol and is used for encryption and authentication of the downloaded or uploaded data between the server and the client. The authentication serves to ensure that each side can verify the identity of the connection partner and secure data transmission takes place. [1]
The integrity of the downloaded file can be checked using hash values (scatter function values). The provider of a download creates checksums according to the Message Digest Algorithm 5 (MD5) developed in 1991, which are provided as separate files, for example. After the transfer has taken place, the error-free transfer is verified by the recipient using a special program to create the MD5 checksum from the transferred file and compare it with that of the provider. If the two sums match, the data transfer is extremely likely to have been completed. However, the downloaded file may still be corrupt or infected with malware (malicious program) andComputer viruses may be infected, [2] since the MD5 function is no longer considered secure, since it is possible with reasonable effort to generate different messages that have the same MD5 hash value.
The term download is often interpreted in a general way to mean that received data is to be stored permanently or at least to be stored only temporarily.
In contrast, however, the term download is taken from the related data transmission method of streaming , which means that received data can be used immediately while the transmission is not yet complete. If the general definition of the term download were to apply, this would mean that the data can only be used if it has been received in its entirety.
In this context, download specifically means "receive and store" rather than just "receive".
An important criterion for the distinction is also the data transmission via e-mail . If data is sent by e-mail, this data is only sent as an attachment (attachment). It is not a download in the specific sense.
A download always depends on the available data transmission rate between server and client. On the one hand, this has an absolute limit in terms of the physical limits of the respective transmission channel or the specifications of the respective devices. On the other hand, when using the Internet, it is more relevant that the provider or providers between client and server in most cases deliberately throttle the data transmission rate in order to ensure consistent treatment of customers.
