Are "certificate", "key" and "keystore" different words for the same thing?

Question

I am having trouble with some signing issues, and I've seen many references to certificates, keys and keystores all used in a way that suggests to me that they are all different words for the same thing. Am I right?

Answer 1

Definitely no.

A certificate is a public key that has been signed by a certificate authority - usually a trust-center.

A keystore is a database for keys and certificates.

Answer 2

The first paragraph should answer all of your questions :-)

http://developer.android.com/tools/publishing/app-signing.html

Answer 3

Certificate is the Encrypted Cert
Key is the Encryption Key used to decrypt the Certificate
Keystore is where all of your known Keys are stored.