For other uses, see RF (disambiguation) . Radio frequency (RF): any of the electromagnetic wave frequencies that lie in the range extending from around 7003300000000000000â 3 kHz to 7011300000000000000â 300 GHz, which include those frequencies used for communications or radar signals.owever, since the antenna will pick up thousands of radio signals at a time, a radio tuner is necessary to tune into a particular frequency (or frequency range). This is typically done via a resonator â in its simplest form, a circuit with a capacitor and an inductor form a tuned circuit.
How the TCP Port 21 Works With FTP. The File Transfer Protocol Uses Port 20 and 21. The File Transfer Protocol (FTP) provides a means to transfer information online, much like how the Hypertext Transfer Protocol (HTTP) is used through a web browser. FTP, however, operates on two different TCP ports: 20 and 21.
Stands for File Transfer Protocol. FTP is a protocol designed for transferring files over the Internet. Files stored on an FTP server can be accessed using an FTP client, such as a web browser, FTP software program, or a command line interface. An FTP server can be configured to enable different types of access. For example, an anonymous FTP configuration allows anyone to connect to the server.