What does PCB board symbol meaning?

dear our engineering :
can u help me to learn me what is the component witch i mark it by red circuit , can u tell me what is that component ?? . i wish to be image clear to you . the circuit is car receiving car .

Probably a transistor or fet, possibly a diode. If you can access a component tester, or can power the circuit up and apply some signals to the parts, you should be able to work it out. To do that you may need to sketch out the circuitry in the vicinity of the parts of interest.
There may be some letters and numbers etched into the top surface, you may need a good magnifier to read them. If so, a web search may turn something up, this has worked for me in the past very successfully,
cheers,
Richard

thanks Dr.richard