How to distinguish between built-in antenna and external antenna?

Built in antenna: The built-in antenna is usually directly soldered to the wireless transceiver module and then embedded into the device together with the wireless transceiver module. The appearance of such devices is generally limited, but it will to some extent affect signal reception (generally not affecting the use of the device). It is more suitable for enclosed areas or scenes where external antennas cannot be connected.
External antenna: External antennas are generally connected to wireless transceiver modules through metal probes or signal extension cables, and are not directly soldered to the equipment. Compared to the built-in antenna, the signal gain of the external antenna will be better. External antennas can be installed in the sky.
The built-in antenna is mainly small, so general built-in antennas include spring antennas, FPC antennas, etc.
External antennas do not have high volume requirements. They are mainly pole antennas, suction cup antennas, and Yagi antennas.
Finally, the wireless transceiver module should choose the antenna based on the actual project situation. The use of built-in and external antennas is not absolute, and actual application scenarios should be the final choice. Antenna is one of the indispensable accessories for wireless transceiver modules. Choosing the appropriate antenna can be of great help to the project.