ば～ほど is a combination of the 接続助詞（せつぞくじょし） (conjunction particle)
ば, and the 名詞（めいし） (noun) ほど. It is used in a similar way to ‘the more ~ the more’ in English. Literally, it just highlights that ‘if it is (A), then the limit of (A) will be controlled only by its extent’.
To use ば～ほど,
ば will be paired with the 仮定形（かていけい） (hypothetical form) of any verb/
い-Adjective (or noun/
な-Adjective with なら on the end), before the same word will be repeated in its 連体形（れんたいけい） (attributive form). After this, a (B) part of the sentence will highlight what the expected result of (A) is.
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いい肉（にく）は噛（か）めば噛（か）むほど味（あじ）が出（で）る。
The more you chew good meat, the more flavorful it gets.
公園（こうえん）は広（ひろ）ければ広（ひろ）いほどいい。
The bigger the park is, the better it is.
ビルは丈夫（じょうぶ）ならば丈夫（じょうぶ）なほど安心（あんしん）できる。
The stronger a building is, the safer you feel.
プロならばプロほど速（はや）く泳（およ）げる。
The more of a pro you are, the faster you can swim.
As
である (the formal version of
だ) may replace な with
な-Adjectives (or なら with nouns), sometimes
である will be used instead of な/なら, in regard to both nouns and
な-Adjectives.
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アプリが便利（べんり）であれば便利（べんり）であるほどユーザーが増（ふ）える。
The more useful an app is, the more users will increase.
職人（しょくにん）であれば職人（しょくにん）であるほど凄（すご）いものが作（つく）れる。
The more of a craftsman a person is, the more likely that they will be able to make something amazing.
When this expression is used with
する verbs, the noun that
する is linked to in the
ば part of the sentence does not need to be repeated in the ほど part.
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漢字（かんじ）の勉強（べんきょう）をすればするほど色（いろ）んな本（ほん）が読（よ）めるようになる。
The more you study kanji, the more you will be able to read various books.
掃除（そうじ）をすればするほど、部屋（へや）が綺麗（きれい）になっていく。
The more you clean, the cleaner your room will get.
Sometimes, the
ば ‘hypothetical’ part of the sentence will be omitted altogether, leaving ほど to perform a similar function by itself.