yes,
it is always one complete process.
you take a lawyer an apply throu him for your residency, at the end of that process you wil receive you temporary(valid for 1 year) residency card and cedular. after one year you have to follow the same procedures again to get both permanently. from there on you just renew the residency every 2 years and the cedular when reached it's expiration date(they are done for different time periods which i did not figured out yet why some are valid longer than others aso, my last cedula i renewed in 2004 and got it valid til 2010, expiration day on the cedula is always your birthday at the year of expiration printed on the cedula, while the expiration date on the residency is the date when you get it plus 2 years/the temporarily one for 1 year).
i had my 'cita' for renewal yesterday(sorrily the gubmin lost the data of stored fotos so for renewal a lot of people like myself have to show up in St Dgo in person to get their picture taken again), have to mention that that one been absolutely hassle free and fast, upon arrival there i had to wait just 20 minutes to get my foto taken and around 15 minutes after that i received my carnet, without paying any kind of VIP or such. i remember times when such took a bit more of time, lol, this time the stuff been very helpful, very friendly and all went smooth, some kind of nice improvement realized from my side compared to prior times dealing with the same department.
your residency card is the document you need when passing customs, so as long as you don't leave /enter the country you should store that one at home at a save place together with your pasport.
the cedula is you ID which you need to carry with you everywhere/all the time. you need it to open a bank account, to deposit or withdraw money, to pay any taxes, to buy a car, aso aso, for any kind of legal transaction.
like americans use their drivers license in the US or Germans use their "Personalausweis" in europe.
welcome to the Isle
Mike