This is the 2624th most frequent Russian word.
увеличивать
To increase.
The word 'увеличить' (to increase) is used in its infinitive form to express the plan to enlarge or make larger the budget.
Мы планируем увеличить бюджет на следующий год.
We plan to increase the budget for the next year.
Here, 'увеличиваться' (to increase, reflexive form) is used to describe an ongoing process of gaining in quantity.
С ростом популярности фильма его сборы начали увеличиваться.
As the film's popularity grew, its earnings started to increase.
In this example, 'увеличить' (to increase) is used to indicate an improvement or enhancement in muscle strength as a result of exercises.