Freehold ownership gives you full rights over the property and the land it sits on. It allows for the property to be inherited or sold without significant restrictions by anyone else.
Leasehold is when the owner holds the right to use and enjoy the property, but the land itself is owned by someone else.
Usufruct gives someone the right to use and derive an income from a property that belongs to another person. It can be either temporary or for the lifetime of the usufructuary.
Co-ownership involves two or more individuals jointly owning a property. Each of the owners will have a share of the property, and decisions related to the property will usually require the agreement of all co-owners.
Horizontal property is commonly associated with condominiums or apartment buildings. In this case, you would own your private living spaces while sharing ownership of the common areas and facilities.
The IMI is an annual tax based on the tax value of the property (not the purchasing value). The tax rate ranges from 0.3% to 0.8% for urban properties and 0.8% for rusting properties. For existing properties, you will inherit the tax value from the previous owner. For new builds, the annual IMI will be provided by the tax authorities at a later stage, but the above should allow you to make a fair assumption.
This is an additional annual municipal property tax. It is levied on the combined fiscal value (and not the sale value!) of all residential properties owned by a tax payer and worth above 600,000 euros as of the 1st of January of each year. There are 3 levels: 0.7% on properties valued between 600,000 euros and 1 million euros. 1% on properties between 1 and 2M. 1.5% if the total is over 2M.
The applicable tax will vary whether you are resident or nonresident. Nonresidents will pay a flat 25% on their income revenues, whereas residents will fall under the taxable brackets and will be taxed as income. In both cases, some expenses will be deductibles.