Difference between TLC272CP and TLC272CDR
They are different packages for the IC. Page 2 of the datasheet shows that CP is a plastic DIP package, and CDR is a small outline package. The R at the end means the ICs come in a reel; if there is no R then they come in tubes.



Performance may depend on the package -- you'll have to check the electrical characteristics in the datasheet to see what the differences are and if they matter to you (the package will be listed at the top of the electrical characteristics table). The package choice is mostly dependent on which you would prefer to use.

Reels are used for large quantities. If you only need a couple hundred (or less) units then you just need tubes. There is no difference in performance between tubes vs. reels -- it's just a difference in how the ICs are shipped.

This is what a reel of ICs looks like:



This is what a tube of ICs looks like: