〜ば〜ほど (ba hodo) expresses a proportional relationship: as one condition changes (represented by the ば-form), another changes in direct response. It means "the more... the more...". It connects the conditional ば-form of a verb/adjective to its plain form. Example: 練習すればするほど、日本語が上手になる。(The more you practice, the better your Japanese becomes.)

前の事柄の程度が進むにつれて、後ろの事柄も進むことを表します。例：読めば読むほど面白い。