The Texas Success Initiative (TSI) website of the Texas Higher Education Coordinating Board defines dual credit and concurrent credit in this way:

Dual credit – Dual credit courses are college courses that also count toward high school requirements. These courses may be taken at the high school (or at the college) during the regular school hours and are taught by a high school teacher with appropriate credentials, or by regular college faculty. Successful completion of the course can earn high school credit as well as college credit.

Concurrent Credit – Concurrent courses are college courses taken by a student outside of high school hours and not associated with the high school or the high school curriculum. Successful completion of the course results in college credit.

Dual credit is a process that allows high school students to enroll in college-level classes to earn both high school and college credit. Dual credit courses may be offered on the high school campus or on the college campus during the school day. High school students may also enroll in a college course from the approved list during the summer or after school with the approval of the high school principal.

The Dual Credit courses are in cooperation with Austin Community College. 

Students who take a college course offered by the high school during the school day will receive simultaneous high school and college credit. During the summer or outside school hours, students who satisfactorily complete pre-approved college courses on the dual credit list will receive high school credit after they present their college courses transcript/grades for placement on the high school transcript.

Dual enrollment credit is accepted by state schools. Students who plan to attend a private or out-of-state school should check with schools on their policy of accepting dual or concurrent enrollment courses. Interested students should check the course catalog online or with counselors who will have updated lists.