The main difference between Certified Copy and Informational Copy is that one is a legal document that establishes identity and the other one does not.
The Certified Copy may only be issued to an authorized person defined by California Health and Safety Code. It is commonly used for business and legal purposes, such as applying for passport, Identification Cards, School ID, Driver Licenses and other government forms of ID or private related business. A certified copy is a legal document, which establishes a person's identity and is accepted by all government agencies.
If you are applying for a foreign passport,you may contact the Embassy or Consulate of that country to inquire about their requeriments around using Certified Copies. In some countries the Certified Copy of the Birth Certificate itself is not sufficient to establish an identity and is not accepted unless you have a seal from the Department of State, called "Apostile". In that case you must contact Alameda County Recorder's Office for more information on how to obtain an Apostile on your Birth Certificate.
The Informational Copy is a copy of the Birth Certificate which cannot establish identity. It is printed on a security banknote paper and it will come with a stamp across the face of the document saying: "INFORMATIONAL, NOT A VALID DOCUMENT TO ESTABLISH IDENTITY. SEC.103526 OF THE CA H&S GOVERNMENT CODE."
An Informational Copy is commonly used for genealogical research or informational purposes. THIS IS NOT A LEGAL DOCUMENT THAT WILL ESTABLISH IDENTITY!