May be the same but are not, definitively are noticeable differences between a scanner and a receiver. Allow me to start with few basic elements then proceed with practical aspects:
- Both receiving signals (obviously no transmit function present)
- While a receiver have a larger receive range of frequencies as well modes / modulation types a scanner is more focused on segments and specific modes (P25, NXDN, DMR besides analogue AM/FM). Receivers most likely do focus on LSB, USB, CW supporting SWL enthusiasts adjusting the bandwidth and filters while scanners are more plug and play
- Scanners are better when it comes to memory management, multiple banks/slots and memories and advanced options for scanning
- Scanners are commonly used to monitor public services communications, modern scanners are able to monitor trunked radio systems which have a central channel (traffic channel) containing channel / frequency allocation for each radio device part of network.
- Scanners possesses advanced features able to close call signal stalking and facilitate monitoring the service more efficient
Whatever we speak about a scanner or receiver and frequency user (either a governmental or private entity) decides encrypting the communication there comes the limitations, proprietary ciphers or encryption methods are applied which limit the usage.
On the top of the fact that scanning (using a scanner) may be prohibited in a large number of countries, decryption of encrypted communications may be a felony.
Decryption of communications may not be a technical limitation but may be a legal limitation, buying such as equipments or feature to existing equipments may require governmental credentials.