
tippen
to type
To enter text with your fingers on a keyboard of a computer, typewriter, or smartphone.
Sie kann sehr schnell mit zehn Fingern tippen.
She can type very quickly with all ten fingers.
to type / guess / tap
Loading your saved state.

to type
To enter text with your fingers on a keyboard of a computer, typewriter, or smartphone.
Sie kann sehr schnell mit zehn Fingern tippen.
She can type very quickly with all ten fingers.

to guess
To make a guess or prediction about the outcome of an event, often in betting or games.
Ich tippe, dass Deutschland das Fußballspiel gewinnt.
I guess that Germany will win the soccer match.

to tap
To touch someone or something briefly and lightly with the fingertip.
Er tippte mir auf die Schulter, um meine Aufmerksamkeit zu bekommen.
He tapped me on the shoulder to get my attention.

to suspect
To suspect, based on signs or evidence, what the cause of something is or who is responsible for something.
Nach der Untersuchung der Spuren tippt die Polizei auf Brandstiftung.
After examining the evidence, the police suspect arson.
When it comes to computers, smartphones, or keyboards, 'tippen' always means to enter text. Typical objects are 'eine Nachricht' (a message), 'eine E-Mail' (an email), or 'einen Brief' (a letter).
Ich muss meinem Chef schnell eine Antwort tippen.
I need to quickly type a reply to my boss.
To express a guess, 'tippen' is used either with a subordinate clause with 'dass' (that) or with the preposition 'auf' + accusative.
Ich tippe, dass die Gäste bald kommen.
I guess that the guests will come soon.
When 'tippen' means a light touch, it is often used with the preposition 'auf' and an accusative object that indicates the place being touched. The person being touched is in the dative.
Der Lehrer tippte dem Schüler auf die Schulter.
The teacher tapped the student on the shoulder.
In the meaning 'to suspect who or what is responsible', 'tippen' is always used with the fixed preposition 'auf' followed by an accusative object.
Die Ermittler tippen auf einen technischen Defekt als Unfallursache.
The investigators suspect a technical defect as the cause of the accident.
to write
Both words can refer to text on a computer or smartphone. Schreiben emphasizes composing the content or communicating in writing, while tippen explicitly refers to entering text with your fingers on keys. Depending on the situation, both can be appropriate.

Ich tippe die Nachricht auf meinem Smartphone.
I am typing the message on my smartphone.
Ich schreibe meiner Schwester eine Nachricht über den Ausflug.
I am writing my sister a message about the trip.