CELTA is more widely known than Trinity's Cert TESOL, but both are recognised by such organisations as the British Council as being of equal value.
You may be interested in a discussion here TEFL vs CELTA vs TESOL . There are other threads in this forum if you search.
Good luck with your course.
ps. You will see CELTA mentioned in job advertisements more than the Trinity Cert. Don't let that put you off. Most employers are happy with either. Any school that does not know about Trinity is probably not worth worrying about.
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