Disability discrimination is when a person with a disability is treated less favourably than a person without the disability in the same or similar circumstances. For example, it would be 'direct disability discrimination' if a nightclub or restaurant refused a person entry because they are blind and have a guide dog.
This is very rampant in society because of negative attitudes towards disability. That's where awareness comes in, and sometimes legislation especially where there are laws against a particular discrimination eg discrimination of persons with disabilities in the workplace.
It is also disability discrimination to think that persons with disabilities are superhuman. For example, it is a common myth that all persons with Down Syndrome are geniuses.
Implicit biases, which Charlesworth described as “more automatic and less controlled” than more conscious explicit beliefs, are usually widespread in society and tend to come from personal experiences, upbringing, and the media. One great disability bias would be being viewed as generally weak that's why people engage us in a demeaning manner simply because we don't retaliate. That is why we have been overlooked for the longest time because we are thought to be weak.
Unconscious bias, where someone perceives for example you need help always and mighty not let you do the thing. It might limit you as a PwD and make you feel weak sometimes.