Having had a jheri curl in my lifetime - EONS ago - they are not the same as a texturizer. As curlycrl said, a texturizer is a relaxer with lye, no-lye, etc. normal relaxer. Put in the relaxer, wash it out a short time later.
With the jhericurl, relaxer is applied, washed out, rolled and then some other stuff is put in to lock in the curl - much like a caucasian hair perm. The second solution stinks.
If you have a perm, the jheri curl does not mesh well with it - jheri curls use a thio-based cream and putting jheri curl over a perm or vice versa is a no-no unless you're only doing the new growth which means a very short cut for either process if you're switching.