Mind uploading is the hypothetical process of copying, moving, or simply reassociating one's memories, personality, consciousness, and/or personal identity from their original physical system (the brain primarily) to another physical system, most likely a computer of some sort.
Mind uploading is considered the likely long term solution to life extension to protect against physical harm. Such prospective technology and whether a 'self' or personal identity can be copied or moved to, or reassociated with, another substrate is a popular debating point amongst transhumanists and futurists.
Mind uploading is a key piece of technology required to go beyond potential biological immortality into posthuman transhumanism. It has proposed that mind uploading is the likely progression of alien intelligence wherever it arises in the cosmos and that we should conduct SETI along such lines. Similarly, mind uploading has been proposed as a required prerequisite for feasible interstellar travel.