There are very few people in this world who truly enjoy paying taxes. One of the least liked taxes in Canada is capital gains tax, that you pay whenever you sell an asset for more than you paid for it.
There is an exemption for a principal residence – if you own a home that you live in, you do not have to pay tax on the gain when you sell it (as long as you did not rent out more than 50% of it to tenants). You can also run into trouble if you own a duplex or triplex and live in one unit while renting out the others.
If you are concerned about whether the tax applies, get advice from an accountant before you sell so that you know what your bottom line will be.