Counselor:
To become a licensed counselor, someone must complete a master's degree in counseling and then complete hands-on work as a counselor (under supervision). The number of required hours of hands-on training varies by state. Many counselors specialize in addiction treatment for drug and alcohol abuse, and the majority receive training in psychotherapy techniques. In terms of substance abuse issues, where therapists deal specifically with healing the root causes of a person's addiction (childhood, trauma background, etc.), counselors deal with the current day-to-day needs of the person. This involves what's called case management, which can include things like housing (which halfway house are you eligible for, or where are you going to live after you get out of a treatment center?); child care (how can you you get your child back if custody is jeopardized by addiction issues?); employment services (informing you about job placement programs), etc. Many times, counselors can also help with interventions, whereas most therapists do not.
Ph.D:
A Ph.D, also known as a doctoral degree, is one of the most advanced academic degrees there is. It can take 4-8+ years to complete a Ph.D program. Getting a Ph.D involves advanced training in research and evaluation (i.e. looking at other research studies that already exist and making connections between them), as well as completing original research in the form of a dissertation. A person can hold a Ph.D in addition to other degrees, so for example you can be an MD with a Ph.D or LPC with a Ph.D. Some people with Ph.Ds can specialize in substance abuse rehabilitation. Those with doctoral degrees are generally held in high regard within the academic and wider community (they have a lot of prestige), and generally charge higher prices for their services if they are in private practice. They do not generally help with interventions.
LPC:
In order to become a Licensed Professional Counselor (LPC) in social work, a person must have a master's degree in counseling. Depending on the state, an LPC may also be called a Licensed Mental Health Counselor (LMHC). An LPC specializing in social work will look not just at a person's drug or alcohol addiction issues, but their economic and social status, their home environment, and other factors when determining a treatment plan for that patient. They are sensitive to issues like whether a person struggling with addiction has a safe home environment in which to recover (or whether they may need to go to a halfway house); whether a person has a job that will help support them in recovery or whether they need to change jobs, etc. Counselors help with the practicalities of everyday life and what will help support sobriety.