What does error message "avrdude: stk500_getsync (): resp=0x00" mean?

This now two ATmega328 chips I've inserted into an Arundunio Uno and regardless of what I try to upload, I get this error message.

Has some encountered this issue and if so, any suggestions or solutions you'd like to share. Totally lost.

Question, Can I insert a new ATmega328 into an Uno, program it, pull it from the Uno, insert it into a project, run it and re-pull it from the project and reinsert it into the Uno for program changes? Is there an issue doing that and does that somehow screw up the synchronization between the chip and something on the Uno?

Appreciate any assistance correcting this issue.

Thanks

New chips will have different fuse settings and probably won't work until you correct that. Plus a new chip won't have a bootloader on it.

See this post about "breadboard" Arduinos. There is a sketch there that should fix the fuse setting and upload the bootloader: