Inflation

Inflation is the rate at which the general price level rises over time, eroding how much a fixed amount of money can buy. It's most commonly measured as the year-over-year percentage change in the Consumer Price Index.

Inflation matters enormously for bond markets: bond payments are usually fixed in dollar terms, so higher expected inflation erodes their real value, which pushes yields up (and prices down) to compensate. It's also the primary target the Bank of Canada manages through the overnight policy rate.