What is the difference in ethics and morals

In our common, everyday speech, ethics and morals are used more or less interchangeably. Both are concerned with what's right and wrong, how we conduct ourselves toward others, and so on. However, some scholars have argued that there is a slight but significant difference between the two, one that relates to their respective sources. On this account, ethics generally refers to rules of moral conduct that are external to the individual agent. Examples would include business ethics, where those engaged in business practices are expected to adhere to certain standards imposed upon them.
This example is particularly instructive in highlighting the distinction between ethics and morals because it shows that there is often a clash between them. What is considered sound from an ethical business perspective may not be regarded as moral. For instance, lawyers will defend their criminal clients in court even though they know full well that they're guilty. In terms of business ethics, this is perfectly acceptable; morally speaking, not so much.
Morals, then, tend to be individualized, internalized, and then acted out by the moral agent as part of her daily life. They tend to derive in the most part from family, society and various religious traditions, but the individual still chooses to live by such moral codes. In that sense, they can be said to express the moral agent's autonomy. Morals can of course change over time and differ widely from place to place. Yet they tend to have a much greater degree of consistency; but then, they have to if they're going to provide us with the appropriate guidance in making choices in our lives.
Ethics tend to be much more flexible. But then, they have to be, too. External standards such as legal and medical ethics need to move with the times, taking into account developments in, respectively, law and medicine. Medical ethics of the 19th century would most certainly not be appropriate today. Yet the myriad moral quandaries served up by the practice of medicine remain more or less unchanged.