Is a usb cord and a charger the same thing?

"Charging cord" is a broad term commonly used in reference to any cord coupling a device with a power supply. This could be in the form of an AC wall charger that plugs into an electrical outlet or a USB cable that supplies a DC current, among others. "A cable used to connect to a computer" is referring to the latter and is commonly called a "sync chord". It often does more that and is used to transfer data from a computer to the device or vice-versa. However, such as in the case of Apple's iPod Shuffle, the sync chord does not use the USB interface but rather an alternative.