I see a lot of aides (and others) use these terms all the time. They get the two mixed and up and this causes much confusion for many people.

“Right To Work” is about union membership.

Each state has statutes on their books about whether a union can require ALL unionized employees to be members of the union, regardless of what the employee wishes at any given place of employment.

A Right to Work law guarantees that no person can be compelled, as a condition of employment, to join or pay dues or “fees” to a labor union. Such a law also reaffirms and strengthens the existing federal labor-law provisions that bar hiring discrimination against union members. Section 14(b) of the Taft-Hartley Act affirms the right of states to enact Right to Work laws. Currently 22 states have passed such laws.
Alabama, Arizona, Arkansas, Kansas, Florida, Georgia, Idaho, Iowa, Louisiana, Mississippi, Nebraska, Nevada, North Carolina, North Dakota, Oklahoma, South Carolina, South Dakota, Tennessee, Texas, Utah, Virginia, and Wyoming.

“Employment At Will” Is About Employment Terms
This term means that employment is presumed to be voluntary and indefinite for both employees and employers, under the Doctrine of Employment at Will. A employer may fire an employee for no reason, for fair and unfair-but not ILLEGAL reasons, and layoff people with no reason.

On the other hand, employees may quit a job for no reason, for fair and unfair reasons and give no notice. The doctrine works both ways. All states adhere to this doctrine; however each state mandates what are legal and illegal reason for termination. Of course, being fired because of your age, sex, your religious affiliation, sexual orientation and race are illegal. You should know what your states stance is on this- there are no lists online that I can find that detail all states.