Cephalosporins are a group of antibiotics.( If you are neither a medical student, doctor, or pharmaceutical chemist, this page may not benefit you.)  

Cephalosporins are classified in to a complex 4 generation systems that include about 20 to 25 drugs with similar looking names. This classification is very difficult to remember, but it is highjly asked for various medical exams.

I have a code ( mneumonic ) to remember it. Even this is not a 100% solution, for the rest you have to byheart it.

Oral Or Parentral 

cefotaxime, ceftriaxone, cefuroxime and anything that start with "cef" or "ceph" and have a "tin", "thin", "z", or "pi" in the name is parentral and others are oral

For example: cefoperazone, cephalothin,cefoxitin,cefpirome etc are parentral cephalospotins.

1st Generations

Cefradine and any cephalosporin with a standalone "l" belongs to first generation.

For example: cephalothin, cefazolin,cefadroxil,cephalexin

Please note: cefaclor, has an "l", but it is not stand alone, instead it is combined with a consonant c. cl is not standalone, but col or cal

3rd generation 

cephalosporins of third generation contains "cef" followed by ( a,e,i,o,u) - optional and then either p,d or t.

For example: ceftibuten, cefdinir, cefoperazone etc

4th Generation

they have pi in the name

Revision

cefpirome= 4th generation (pi)  and parentral (pi)

cefoperazone= 3rd generation (fop), parentral (z)

cefaclor= 2nd generation (fit to no other criteria) oral (do not fit for parentral)

Hope this artcle help you much. I am not responsible any new cephalosporins invented after posting this article, that do not fit this mneumonic