המונה החכם שומר את היסטוריית הצריכה.

In Hebrew, adjectives normally come after the noun they describe.

So:

• מונה חכם = a smart meter
• המונה החכם = the smart meter

The ה is the definite article, equivalent to the.
When a noun is definite, its adjective must also be definite.

So המונה החכם literally works like the meter the-smart, but in natural English that becomes the smart meter.

שומר is the present-tense form (historically a participle) of the verb לשמור, meaning to keep, guard, preserve, save, store.

In Modern Hebrew, there is usually no separate present-tense word for is / am / are.

So:

• המונה החכם שומר... = The smart meter keeps / is keeping / stores...

Hebrew just uses the present form directly, without adding a word like is.

Also, שומר is masculine singular, matching המונה.

את marks a definite direct object.

It does not get translated into English, but it tells you that the next word or phrase is the thing being acted on.

Here:

• שומר = keeps / stores
• את היסטוריית הצריכה = the consumption history

So את is there because היסטוריית הצריכה is a definite object.

A very important rule:

• את is used before a definite direct object
• It is not used before an indefinite direct object

היסטוריית is the noun היסטוריה in the construct state (called smikhut in Hebrew).

This structure is used when one noun is linked to another noun, often like English X of Y.

So:

• היסטוריה = history
• היסטוריית הצריכה = history of the consumption / the consumption history

The ending changes because the noun is attached to what comes after it.

This is very common in Hebrew. Compare:

• ספר = book
• ספר התלמיד = the student's book

Similarly:

• היסטוריה = history
• היסטוריית הצריכה = consumption history

Because in a construct chain, definiteness is usually shown on the last noun, and that makes the whole chain definite.

So:

• היסטוריית צריכה = consumption history / a history of consumption
• היסטוריית הצריכה = the consumption history

Even though היסטוריית itself does not have ה, the phrase is still definite because הצריכה is definite.

That is also why the sentence uses את: the object is definite.

Yes. Hebrew could also use a של phrase, for example:

• ההיסטוריה של הצריכה

That also means the history of the consumption.

But היסטוריית הצריכה is more compact and often sounds more natural in formal, technical, or written language.

A rough comparison:

• היסטוריית הצריכה = more compact, noun-chain style
• ההיסטוריה של הצריכה = more explicit, more like the history of the consumption

Both are grammatical, but the construct form is very common here.

Because מונה is a masculine singular noun.

In Hebrew:

• adjectives agree with the noun in gender and number
• present-tense verb forms also agree in gender and number

So:

• מונה = masculine singular
• חכם = masculine singular adjective
• שומר = masculine singular present form

If the subject were feminine singular, the forms would change. For example:

• המערכת החכמה שומרת את הנתונים
  The smart system keeps the data

Here:

• מערכת is feminine
• so חכמה and שומרת are feminine too

Yes, the basic meaning of שומר is related to guarding or keeping, but in Modern Hebrew it is also widely used for:

• keeping
• preserving
• saving
• storing

So in a technical sentence like this, שומר את היסטוריית הצריכה can mean:

• keeps the consumption history
• stores the consumption history
• saves the consumption history

The exact English translation depends on context, but the Hebrew is completely natural.

A simple pronunciation guide is:

ha-mo-NE ha-kha-KHAM sho-MER et his-to-ri-YAT ha-tsri-KHA

A more connected transliteration:

ha-mone ha-khakham shomer et historiyat ha-tsrikha

A few sound notes:

• ח is a throaty sound, like ch in German Bach or Scottish loch
• צ sounds like ts
• את here is pronounced et

So if you want a smooth reading:

ha-mone ha-khakham shomer et historiyat ha-tsrikha