Oxygen is more electronegative than carbon, thus the hydrogens alpha to ethers are more acidic than in simple hydrocarbons. They are far less acidic than hydrogens alpha to carbonyl groups (such as in ketones or aldehydes), however.
Depending on the groups at R and R', ethers are classified into two types:
1. Simple ethers or symmetrical ethers; e.g., Diethyl ether, dimethyl ether, etc.
2. Mixed ethers or asymmetrical ethers; e.g., Methyl ethyl ether, Methyl phenyl ether, etc.