Set the topic of a sentence
は marks the topic, telling the listener what the rest of the sentence is about.
JLPTN5
Topic は ...~ wa ...
as for [topic]; speaking of [topic]
Example Sentences

Excuse me, where is the station?

Welcome home, how was today?
Written with the kana for ha but pronounced wa, は sets up the topic and the rest of the sentence comments on it. It often overlaps with the subject but is broader, and it can also draw a contrast between two things. Compare it with が, which instead points out the specific subject.
Tips and Common Traps
Hana· Key point
は is how you introduce yourself or set up what you're talking about — 私は (as for me) is one of the first things you'll say in Japanese.
Build the Sentence
JLPT N5I am a student
Arrange the words in the correct Japanese order:
わたし私
I です
is / am (polite) は
what it's about · said "wa"がくせい学生
student