Noun: Laptop computer, notebook, notebook computer.
Kannettava is an adjective that means ”portable.” Kannettava is the passive present participle of kantaa, which means ”to carry” or ”to bear.” Participles are verbal adjectives, and literally, kannettava can be thought as meaning ”carry-able.”
Tietokone means ”computer.” (Literally, ”data machine.”)
A shortened form of kannettava tietokone is just kannettava. Or colloquially, in spoken Finnish, you often hear läppäri which comes from the English word ”laptop.”