SoCal also includes Orange Country--the TV calls it the OC--most folks go by the name of the city, like Newport Beach and Huntington Beach... And SoCal also includes San Diego and all of its counties.
In San Diego, there's Golden Triangle near La Jolla. Mission Beach and Pacific Beach or P.B. are not part of the triangle. The triangle is demarcated by the freeways: I-5 corridor, the 52 and I-15. Beyond the 52, it becomes North County and Northest County.
Then there's Mission Valley where the Qualcomm Stadium is. The downtown is usually called the Gaslamp Quarter, but that's where all the tourists go. South of I-8 up until you get to San Diego State University, is call The Rim.
The more south you get before Imperial Beach--not to be confused with Imperial County in Descanso is--the names are refered to their cities... Then there is the East County that expands more north every day for some reason--like El Capitan and Rancho Santa Fe.
My parents reside in the Del Cerro-San Carlos area of San Diego very close to Cowles Mountains. I guess you tell your location based on the visibility of individual mountains in San Diego.
I use to live in Mission Valley.
Now I live on the Eastside of King County near Seattle in the Pac-North West...